A system of constitutional checks and balances has never won a popularity contest among figures on both the Right and the Left who seek to use the state as an instrument for the salvation of society. This idea, however, is not new; it has ancient roots in the writings of Polybius and found modern expression in Montesquieu’s defense of checks and balances in The Spirit of the Laws. In the case of the United States, which could be said to have established the modern standard for a system of checks and balances, ideologues on both the Left and the Right have never fully reconciled themselves, and perhaps never will reconcile themselves, to the US Constitution and its system of checks and balances, which seeks to restrain transient majorities from exercising unchecked power.

　　Although the principle of checks and balances has been a cornerstone in the defence of liberty across the world, in contemporary times—when politics seems to be operating as agonism on steroids, where every political disagreement has become a kind of life-and-death struggle—checks and balances are increasingly seen as the main obstacle on the road to the land of salvation. For salvationists, the system of checks and balances is not natural and is counterproductive to the life of a country. This sentiment is perhaps best encapsulated by then-Professor Woodrow Wilson, who wrote in his 1908 book Constitutional Government in the United States:

　　Governments are living things and operate as organic wholes. … The makers of the Constitution constructed the federal government upon a theory of checks and balances which was meant to limit the operation of each part and allow to no single part or organ of it a dominating force; but no government can be successfully conducted upon so mechanical a theory.

　　One of the instruments of checks and balances that has been increasingly under attack is the bicameral structure of legislative power. Take, for example, the abolition of hereditary peers from the House of Lords in the United Kingdom by the Labour Government. In the Philippines, there have been calls to eliminate the Philippine Senate. Even in the United States, increasing legislative gridlock across constitutional structures has placed a strain on bicameral arrangements and provided ammunition to critics of bicameral systems. This problem is further amplified by the deference—or, at times, outright pliancy—of members of Congress towards the president of the United States when both belong to the same political party.

　　Legislators within a bicameral system possess a mandate of their own—one that is political, whether directly or indirectly derived, but also constitutional in nature.

　　The usual critiques of bicameral structures are that they generate paralysis and gridlock, impose costs on the taxpayer, and may dilute accountability or obscure rather than curb lobbyist influence. Hence, it should not be surprising that the post-World War II trajectory has seen some states abolish bicameral structures, as occurred in Denmark and Sweden, although the global balance between unicameral and bicameral systems has plateaued; indeed, Peru recently returned to a bicameral system. What is undoubted is that the majority of legislatures across the world are unicameral rather than bicameral. More importantly, however, within most bicameral legislatures the upper chamber is fundamentally weak—for example, the UK House of Lords—or is not equal in power to the lower chamber. For instance, in Germany, the Bundesrat possesses only limited veto powers.

　　As the United States celebrates its 250th birthday this year, it is also an appropriate moment to acknowledge one of its most important contributions to the theory and practice of constitutional government: a bicameral legislature with comparatively strong and co-equal chambers. One might offer an ode to bicameralism in this respect.

　　Yet the United States was not initially committed to bicameralism. Under the Articles of Confederation, the national Congress was a unicameral legislature. As delegates met in Philadelphia for the 1787 Federal Convention, however, bicameralism became a central feature of the new constitutional design.

　　Publius articulated the logic for comparatively strong and co-equal chambers in Federalist #51, advocating safeguards against legislative tyranny. Thus, Publius writes:

　　In republican government, the legislative authority necessarily predominates. The remedy for this inconveniency is to divide the legislature into different branches; and to render them, by different modes of election and different principles of action, as little connected with each other as the nature of their common functions and their common dependence on the society will admit. It may even be necessary to guard against dangerous encroachments by still further precautions. As the weight of the legislative authority requires that it should be thus divided, the weakness of the executive may require, on the other hand, that it should be fortified.

　　The need for a bicameral legislature as a check on transient passions and majorities is further reinforced in Federalist #62. Publius argues: “The necessity of a senate is not less indicated by the propensity of all single and numerous assemblies to yield to the impulse of sudden and violent passions, and to be seduced by factious leaders into intemperate and pernicious resolutions”. He further adds in Federalist #63 that the Senate functions as a cooling mechanism for political passions: “such an institution may be sometimes necessary as a defence to the people against their own temporary errors and delusions … there are particular moments in public affairs when the people, stimulated by some irregular passion, or some illicit advantage, or misled by the artful misrepresentations of interested men, may call for measures which they themselves will afterwards be the most ready to lament and condemn.”

　　Bicameralism in the United States not only functions as a feature that fosters civic friendship and compels compromise on deeply divided policy questions, or, in short, as Yuval Levin argues in his book American Covenant, unity. In Publius’s words, however, there is something more fundamental about bicameralism: it represents a crucial safeguard for liberty, particularly in the context of transient majorities and passions that may seek to trample upon liberty in their quest for salvation. Freedom is protected not only by two strong and coequal chambers, but also by the manner of their elections, their constituencies, their procedures, and their specific constitutional roles.

　　Yet Publius understood that structuring two strong, coequal chambers with distinct election cycles, constituencies, procedures, and constitutional roles was insufficient. The institutions themselves required human agents capable of working both for and within the bicameral structure. To achieve this, lawmakers within these chambers had to be actively ambitious—jealous in preserving their institutional authority. As Publius famously observes in Federalist #51, “ambition must be made to counteract ambition.” To prevent the abuse of power both within the legislature and across the broader constitutional structure, the system relies upon this competitive drive for dominance to keep power in check.

　　Herein lies the challenge affecting bicameral legislatures across the world, particularly those few with strong and coequal chambers: there often appears to be a lack of ambition among members of the upper chambers. Since lower chambers and the executive are more susceptible to transient majorities, members of upper chambers are frequently pressured to fall in line with the “mandate” granted by the people to the executive and the lower chamber. Furthermore, even among members of lower chambers, ambition may be attenuated, as the executive “mandate” is often understood as requiring alignment with the government programme supported by the electorate.

　　That is not to say that, in every political question, the upper chamber invariably falls in line with the “mandate” of the executive or transient majorities. For example, the relatively weak House of Lords has, recently, halted legislation that would have legalised assisted suicide in the United Kingdom—legislation passed by the democratically elected and more powerful House of Commons. Even in the United States, Republican senators who hold a majority have not always aligned with the Trump White House; for example, in the case of Matt Gaetz, the president was reportedly compelled to withdraw his nomination for attorney general due to opposition from Senate Republicans. Nevertheless, these are only a few examples—and the keyword here is “few”—suggesting that the broader trajectory is one in which members of both upper and lower chambers increasingly fall in line with the government agenda derived from the executive “mandate.”

　　If Publius’s words regarding the importance of bicameralism for the preservation of liberty are correct—and I believe they are—then the increasing attacks against the institution, together with the lack of ambition among members within bicameral legislatures, represent a danger to liberty. Although, in the case of the United States, its particular constitutional particularities make it difficult for a single party to control all branches of government for an extended period of time, thereby allowing competition between factions to operate as an additional safeguard for liberty, the danger becomes more acute when both the executive and the legislature are controlled by the same faction and the members of the bicameral legislature lack ambition.

　　Bicameral systems play a vital role within systems of checks and balances, particularly in contexts where the executive and legislature are controlled by the same faction.

　　Therefore, if bicameralism is to fulfil its role in safeguarding liberty, particularly in contexts where the executive and the legislature are controlled by the same faction, legislative members must recover their ambition: the ambition to protect their constitutional roles and powers, to assert institutional independence, but also the ambition that arises from recognising that they too possess, directly or indirectly, a “mandate” from the electorate. This latter point is particularly important, since in representative government the executive alone does not possess a mandate; legislative members are not merely delegates tasked with enforcing the executive’s will.

　　Legislators within a bicameral system possess a mandate of their own—one that is political, whether directly or indirectly derived, but also constitutional in nature. If legislators recover this ambition, the legislature can once again perform a healthy and effective role within the broader system of checks and balances.

　　An effective example of this ambition operating within a context in which a single faction controls both the legislature and the executive can be found in my native Puerto Rico, particularly in the figure of the president of the Senate, Thomas Rivera Schatz. For example, in 2019, Rivera Schatz initiated legal action to prevent Pedro Pierluisi from being sworn in as the successor to Governor Ricardo Rosselló, who had resigned in disgrace, on the grounds of constitutional violations. More recently, Rivera Schatz, currently serving his third non-consecutive term as Senate president, has become embroiled in a political crossfire with Governor Jenniffer González-Colón. Although both belong to the same local party and are affiliated with the Republican Party, the Puerto Rican Senate has rejected and voted down several of the governor’s cabinet nominations and has exercised a robust oversight role, often to the detriment of the González administration. In both of these cases, the lower house—the Puerto Rican House of Representatives—appeared to lack the same ambition in asserting its institutional role and was more closely aligned with the executive “mandate.”

　　What lies behind Rivera Schatz’s ambition to protect the constitutional prerogatives and “mandate” of the Puerto Rican Senate is not entirely clear. It may well reflect political survival or internal party struggles for control. Nevertheless—and this may be a controversial claim for readers familiar with Puerto Rican politics—there is no doubt that Senator Rivera Schatz’s ambition has contributed significantly to the defence of Puerto Rico’s constitutional structure and to maintaining a degree of balance between the legislative and executive branches. In short, this is one example of the potential value of a bicameral system and its role within a system of checks and balances, particularly in contexts where the executive and legislature are controlled by the same faction, provided that members of the legislature retain institutional ambition.

　　In his speech to a joint session of the United States Congress, King Charles III, while praising the similarities between the British and American constitutional traditions, declared: “And those roots go even further back in our history: the US Supreme Court Historical Society has calculated that Magna Carta is cited in at least 160 Supreme Court cases since 1789, not least as the foundation of the principle that executive power is subject to checks and balances.” The reaction to these words, particularly from the Democratic side, was a spirited standing ovation. That standing ovation serves as a timely reminder that bicameral legislatures are, at least in principle, aware of their role within the system of checks and balances and of their contribution to safeguarding liberty. It is a pity, however, that many participating in that ovation perhaps failed to undertake an inner introspection regarding how their own lack of ambition has weakened that system and one of its central components: bicameralism.