On Friday [March 21], a House Appropriations Committee website was so overwhelmed by legislators' wish lists that it crashed, forcing the committee to extend the deadline for earmark requests until Monday. Most members of Congress seem to think the problem with earmarks is like the problem with the committee's server: not any particular person's demands, just all of them together.

On the face of it, the presumptive Republican presidential nominee, John McCain, and the two remaining contenders for the Democratic nomination, Barack Obama and Hillary Clinton, take a different view: All three supported a one-year moratorium on earmarks that the Senate recently rejected by a wide margin. But only McCain has taken a principled stand against the pet projects that legislators love to slip into spending bills.

"We Republicans came to power in 1994 to change government," McCain told the Riverside, Calif., Press Enterprise last year, "and the government changed us. That's why we lost the election: We began to value power over principle."

For the Arizona senator, ever-escalating earmarks symbolized how power corrupted the Republicans. It was not just in the most glaring ways, as when Randy Cunningham, the former Republican congressman from San Diego, exchanged defense earmarks for bribes. It was also in the far more common and accepted practice of using earmarks to reward campaign contributors and buy votes.

More fundamentally, Republicans betrayed their commitment to fiscal restraint (not to mention their responsibility to uphold the Constitution) by spending federal tax dollars on local matters. As McCain puts it on his campaign website, earmarks "divert taxpayer dollars to special interest pet projects with little or no national value." He warns that "every dollar irresponsibly spent by Congress is a dollar diverted from pressing national priorities."

I don't necessarily agree with McCain's national priorities or his notion of fiscal responsibility, which includes an open-ended commitment to an ill-considered and increasingly expensive war in Iraq. But at least he makes the point that the federal government was not created so that taxpayers in New Jersey could pay for bridges in Alaska or sweet potato research in Mississippi.

"Pork barrel spending," McCain says, "is an insult to taxpayers, a waste of public resources, and an abdication of our leaders' responsibility to be good and honorable stewards of the public treasury, for the benefit of all Americans, not just a few." He says he wants to end, not mend, earmarks, and in the meantime he declines to seek them for his own state.

By contrast, Obama seems to think the main problem with earmarks is a lack of visibility. To his credit, the Illinois senator co-sponsored (along with McCain) legislation that has made information about earmarks more readily available than ever before. He says earmark spending should be reduced, suggesting much of it is inappropriate.

Yet Obama, who is in his first term, also complains that earmarks are distributed based on seniority rather than "merit," and he worries that obtaining funding is too difficult for cities and nonprofit groups. One man's pork is another's job-generating, life-enhancing boon. Obama surely thinks all his earmark requests, which last year included money for theaters, museums, and hospitals in Chicago, are perfectly justified.

That goes quadruple for Hillary Clinton. According to Taxpayers for Common Sense, Clinton placed 10th in the Senate pork pulling competition last year, obtaining a total of $342 million in earmarks, almost four times Obama's haul. In the 2008 defense authorization bill, the New York senator received $148 million in earmarks, more than anyone except the chairman of the Senate Armed Services Committee. Her earmark total from 2002 to 2006 was $2.2 billion.

But according to Clinton, these expenditures, including money for "local artist space" in Buffalo, firefighting equipment in Oswego, "clean fuel buses" in Syracuse, the Historic Seneca Knitting Mill in Rochester, and the Eleanor Roosevelt Center in Val-Kill, are not earmarks. They are "Investments in New York," and she is "very proud" of every one.