WASHINGTON -- Congress is less divided by partisanship than it is united by devotion to the practice of protecting incumbents. Doing this with, for example, the bipartisan embrace of spending "earmarks" is routinely unseemly. But occasionally, incumbent protection is also unconstitutional.

It was in 2002, when Congress was putting the final blemishes on the McCain-Feingold law that regulates and rations political speech by controlling the financing of it. The law's ostensible purpose is to combat corruption or the appearance thereof. But by restricting the quantity and regulating the content and timing of political speech, the law serves incumbents, who are better known than most challengers, more able to raise money and uniquely able to use aspects of their offices -- franked mail, legislative initiatives, C-SPAN, news conferences -- for self-promotion.

Not satisfied with such advantages, legislators added to McCain-Feingold the Millionaires' Amendment to punish wealthy, self-financing opponents. The amendment revealed the cynicism behind campaign regulation's faux idealism about combating corruption.

The amendment says: When a self-financing House candidate exceeds the personal spending threshold of $350,000, his opponent gets three benefits. First, the opponent can receive contributions triple the per election limit of $2,300 from each donor. Second, the donors' now-tripled contributions are not counted against those donors' aggregate contribution limits for the two-year election cycle. Third, the opponent is permitted to coordinate with his political party committee unlimited party expenditures that otherwise would be limited by statute. Senate campaigns are subject to similar provisions, which are even more generous to candidates opposed by wealthy, self-financing individuals.

In 2006, Jack Davis, a wealthy Buffalo-area Democrat, self-financed his House campaign against Rep. Tom Reynolds who, as a four-term incumbent and a former chairman of the National Republican Congressional Committee, knows how to raise money. Benefiting from the additional advantages conferred by the Millionaires' Amendment's provisions, Reynolds narrowly won, 52-48.

Davis wants the Supreme Court to rule that the Millionaires' Amendment unconstitutionally burdens the First Amendment right of political advocacy and violates the Constitution's guarantee of equal protection of the law. The Millionaires' Amendment does both -- and it reveals how the corruption rationale for campaign finance regulation is a charade.

In 1976, examining a 1974 law restricting both campaign contributions and expenditures, the court affirmed two principles. First, corruption arises from quid pro quo arrangements connecting contributions with particular actions of a public official. Second, because corruption arises from contributions, restrictions on expenditures are much more problematic, constitutionally.

The court noted that candidates spending their own money reduce their susceptibility to coercive pressures, and hence serve the purported purpose of regulation -- preventing corruption. So the court rejected the limits on candidates' personal expenditures, and dismissed as merely "ancillary" the objective of "equalizing the financial resources of candidates." Furthermore, in 2001 the court affirmed the limits on party-coordinated expenditures because they are "tailor-made to undermine contribution limits." With that in mind, reread, four paragraphs above, the third provision of the Millionaires' Amendment.

So, that amendment punishes candidates who use their own noncorrupting money -- self-financing candidates cannot corrupt themselves -- to disseminate their political speech. Such candidates are penalized for exercising a fundamental right -- political speech -- that Congress cannot constitutionally curtail.

The amendment does this by increasing the access of candidates opposed by wealthy candidates to what the authors of McCain-Feingold supposedly considered the corrupting sort of money -- political contributions from donors who can give triple the amount that McCain-Feingold says can corrupt (or in the case of Senate candidates, six times that amount).

Furthermore, incumbents can benefit from the Millionaires' Amendment even when they have amassed, as most can, substantial war chests. McCain-Feingold's authors wrote this provision while pretending to reduce the influence of donors, but while actually engaged in incumbent protection.

Davis' appeal to the Supreme Court asks: "If the answer to the corrupting influence of campaign donations is the application of uniform limits, how can the answer to noncorrupting expenditures be found in higher limits made available only to those candidates most susceptible to corruption?" If the court answers that question reasonably, it will accelerate the unraveling of McCain-Feingold, the most pernicious -- and for incumbents, the most audaciously self-serving -- law ever enacted to abridge First Amendment freedoms. Meanwhile, both parties increasingly try to recruit self-financing candidates, because "reforms" imposing limits on the size of contributions have increased the cost, in candidates' time and money, of raising campaign funds.

In 1976, the court stressed how crucial it is "that candidates have the unfettered opportunity to make their views known." In 2003, however, the court affirmed McCain-Feingold's fetters on political advocacy. The court has some contradictions to correct and an immediate reason -- the Millionaires' Amendment -- to begin.