Justices to Hear Challenge of Law That Affects Self-Funded Candidates

Clement said the law was carefully tailored to comply with the court's 1976 landmark campaign finance ruling in Buckley v. Valeo. That decision upheld limits on campaign contributions but said candidates could not be restricted in how much of their own money is spent on their campaigns.

Clement said Congress has a legitimate role in reducing the disparities between wealthy candidates and others. "The perception that House and Senate seats may be bought and are the exclusive province of the rich are corrosive perceptions that Congress can seek to address," he wrote.

Davis argues that combating the corruption that could accompany large donations is what the court has approved, not simply leveling the playing field. Even if it had, he maintains, the amendment gives advantages to incumbents by not counting in its complicated formula money they carry over from previous campaigns.

"It's not a millionaire's amendment," Davis said. "It's an incumbent's amendment."

Clement said the numbers do not bear that out. During the first four years after the act was adopted, 110 House and Senate candidates became eligible to receive enhanced contributions under the modified limits, but only six were incumbents, he said.

One of those was Reynolds, who did not take advantage of the law.

Jennifer A. Steen, a Boston College professor who has studied the effects of the amendment, said she has not found many.

"Few candidates have benefited significantly from increased individual contribution limits, and among those who did no candidate enjoyed unfettered party spending,'' she wrote in a paper for the FEC. "Even those candidates who enjoyed Millionaire's Amendment benefits did not do so at the political expense of a self-financer.''

Coincidentally, one who did benefit from the McCain-Feingold provision was the man who may end up being McCain's opponent for president. Barack Obama faced an opponent in the Democratic primary of his 2004 Senate race in Illinois who spent more than $28 million of his own money; Obama took advantage of the increased limits to raise an additional $3 million for his campaign.