Mercer arrived at the Philadelphia convention on 6 Aug 1787. On that day he told his fellow Marylanders that he didn’t think the government set up by the Articles of Confederation “was susceptable of a revision which would sufficiently invigorate it for the exigencies of the times.”
But a couple of days later Mercer told James McHenry “that he did not like the [newly proposed] system, that it was weak—That he would produce a better one since the convention had undertaken to go radically to work, that perhaps he would not be supported by any one, but if he was not, he would go with the stream.”
Remember that Mercer was only twenty-eight years old, younger than all but one delegate, and he had arrived after the other men had been working out issues and compromises for months. I can’t imagine his brand-new proposals were welcomed with any enthusiasm.
Mercer is often grouped with the Anti-Federalists who preferred to keep more power with the states, such as his Maryland colleague Luther Martin. But at the convention, Mercer’s big complaints had to do with the relationship between the branches of the federal government. At times he argued for strict separation of powers, speaking out against Senate approval of treaties (an executive function, he said) and judicial review of laws (a legislative function).
On 14 August, the debate focused on what might seem like a quaint question: whether the President could appoint legislators to positions in the government. On that question, Mercer didn’t want to maintain the separation between executive and legislative. He delivered his longest argument to get into James Madison’s notes, revealing his political philosophy:
It is a first principle in political science, that whenever the rights of property are secured, an aristocracy will grow out of it. Elective governments also necessarily become aristocratic, because the rulers being few can and will draw emoluments for themselves from the many. The governments of America will become aristocracies. They are so already. The public measures are calculated for the benefit of the governors, not of the people. The people are dissatisfied, and complain. They change their rulers, and the public measures are changed, but it is only a change of one scheme of emolument to the rulers, for another. The people gain nothing by it, but an addition of instability and uncertainty to their other evils.Madison added, “On these points he was opposed by Elbridge Gerry.” Gerry was another of the convention’s champions of keeping more power in the states and of limiting the executive power.
Governments can only be maintained by force or influence. The Executive has not force,—deprive him of influence, by rendering the members of the Legislature ineligible to Executive offices, and he becomes a mere phantom of authority. The aristocratic part will not even let him in for a share of the plunder.
The Legislature must and will be composed of wealth and abilities, and the people will be governed by a junto. The Executive ought to have a Council, being members of both Houses. Without such an influence, the war will be between the aristocracy and the people. He wished it to be between the aristocracy and the Executive. Nothing else can protect the people against those speculating Legislatures, which are now plundering them throughout the United States. . . .
Mr. MERCER was extremely anxious on this point. What led to the appointment of this Convention? The corruption and mutability of the legislative councils of the States. If the plan does not remedy these, it will not recommend itself; and we shall not be able in our private capacities, to support and enforce it: nor will the best part of our citizens exert themselves for the purpose.
It is a great mistake to suppose that the paper we are to propose will govern the United States. It is the men whom it will bring into the Government, and interest in maintaining it, that are to govern them. The paper will only mark out the mode and the form. Men are the substance, and must do the business.
All government must be by force or influence. It is not the King of France, but 200,000 janissaries of power, that govern that kingdom. There will be no such force here; influence, then, must be substituted; and he would ask, whether this could be done, if the members of the Legislature should be ineligible to offices of State; whether such a disqualification would not determine all the most influential men to stay at home, and prefer appointments within their respective States.
Mercer left the convention early and opposed ratification of the Constitution. When the nation ratified the plan anyway, he served some terms in the U.S. Congress, allying himself with the Jeffersonian party that included Martin and Gerry. But I don’t think Mercer was with them during the convention.