Washington ? Mitt Romney is an intelligent man who sometimes seems eager to find bushel baskets under which to hide his light. Romney faults Rudy Giuliani for opposing the presidential line-item veto. But Giuliani doesn’t, unfortunately. The facts – not that they loom large in this skirmish – are:

When in 1997 Bill Clinton used the line-item veto, with which Congress had just armed him, to cancel $200 million for New York state, Giuliani harried Clinton all the way to the Supreme Court. It agreed with Giuliani that the line-item veto was an unconstitutional violation of the “presentment” clause. Today, Giuliani says, in defense of what does not need defending (his defense of the Constitution), that he favors amending the Constitution to give presidents such a veto, thereby substantially augmenting what should not be further augmented – presidential power.

In 1996, when a Republican-controlled Congress tried by statute to give Clinton and subsequent presidents a line-item veto, Pat Moynihan’s intervention in the Senate debate began: “I rise in the serene confidence that this measure is constitutionally doomed.” He was vindicated because the Constitution says “every bill” passed by Congress shall be “presented” to the president, who shall sign “it” or return “it” with his objections. The antecedent of the pronoun is the bill, not bits of it.

Forty-three governors have, and most presidents have coveted, the power to have something other than an all-or-nothing choice when presented with appropriations bills. This did not matter in 1789, when the only appropriations bill passed by the First Congress could have been typed double-space on a single sheet of paper. But 199 years later, President Ronald Reagan displayed a 43-pound, 3,296-page bill as an argument for a line-item veto. Today’s gargantuan government, its 10 thumbs into everything, routinely generates elephantine appropriations bills.

But were a president empowered to cancel provisions of legislation, what he would be doing would be indistinguishable from legislating. He would be making, rather than executing, laws, and the separation of powers would be violated.

Furthermore, when presidents truncated bills by removing items, they often would vitiate the will of Congress. Frequently, congressional majorities could not have been cobbled together for bills if they had not included some provisions that presidents later removed.

If Romney thinks a line-item veto would be a major force for federal frugality, he is mistaken. Gov. Reagan used his line-item veto to trim, on average, only about 2 percent from California’s budgets. And much larger proportions of state budgets than of the federal budget are susceptible to such vetoes.

Sixty-one percent of the federal budget goes to entitlements and to interest payments on government borrowing, neither of which can be vetoed. Another 21 percent goes to defense and homeland security. Realistically, the line-item veto probably would be pertinent to less than 20 percent of the budget.

And the line-item veto might result in increased spending. Legislators would have even less conscience about packing the budget with pork, because they could get credit for putting in what presidents would be responsible for taking out. Presidents, however, might use the pork for bargaining, saying to individual legislators: If you support me on this and that, I will not veto the bike path you named for your Aunt Emma.

After a century of the growth of presidential power, and after eight years of especially aggressive assertions of presidential prerogatives, it would be unseemly to intensify this tendency with a line-item veto. Conservatives used to be the designated worriers about the evolution of the presidency into the engine of grandiose government. They should visit the Rotunda for the Charters of Freedom in the National Archives building on Constitution Avenue. There the Constitution is displayed under four large glass plates. Almost half of the glass is required to cover just Article One. That concerns the legislative branch, which is the government’s “first branch” for a reason.

A polite assessment of Romney’s – and Giuliani’s – enthusiasm for a line-item veto would resemble a 19th-century scholar’s assessment of a rival’s translation of Plato: “The best translation of a Greek philosopher which has ever been executed by a person who understood neither philosophy nor Greek.”