Republican leaders urged the Supreme Court yesterday to strike down Missouri's limit on campaign contributions and thereby knock the constitutional props out from under the long-standing $1,000 limit on individual contributions to federal candidates.

In a brief supported by the Republican National Committee, the National Republican Senatorial Committee (NRSC) and the Missouri GOP, Sen. Mitch McConnell (R-Ky.) argued that Missouri's $1,075 gift limit -- and, by extension, the slightly lower federal limit -- violates constitutional guarantees of free speech.

McConnell and many other Republicans have long opposed new restrictions on campaign contributions and instead support an increase in the limit on individual gifts, arguing that the ceiling is unrealistically low and thus encourages less well-regulated forms of giving.

"Faced with rapidly rising campaign costs and the falling real value of contribution limits, candidates and political parties increasingly face a choice between curtailing campaign speech or diverting time from discussion of issues to fund-raising," McConnell argued in the friend-of-the-court brief. "In turn, the accelerating `money chase' prompts calls from regulation activists for more campaign finance regulation."

Ruling on a package of post-Watergate reforms approved by Congress in 1974, the Supreme Court two years later rejected controls on campaign spending but upheld limits on contributions, including the $1,000 cap on gifts by individuals.

But McConnell, who is chairman of the NRSC, which raises funds for senatorial candidates, argued that 25 years of inflation has made $1,000 worth only $302 in today's dollars. If the limit had been adjusted for inflation, it would be $3,306, he said. If it were further adjusted to reflect voting-age population, it would be $4,600, he added.

If the court strikes down the $1,000 as an infringement on political speech, McConnell said he would seek to raise the limit to one of these two levels.

Critics of raising the $1,000 limit have argued that it favors wealthier givers (and Republican candidates), although some have suggested a compromise under which the limit would be raised in exchange for curbs on unregulated "soft money" gifts to political parties. McConnell has opposed such curbs.

Missouri adopted the $1,000 limit for state races in 1994 and indexed it for inflation. It was challenged by a state candidate, upheld by a federal district court but struck down by the Eighth Circuit Court of Appeals last November. Arguments before the Supreme Court are scheduled this fall.

An opposing brief was filed earlier by a bipartisan group of House and Senate members, led by Sen. Jack Reed (D-R.I.), who argued the contribution limit is constitutional.

McConnell's filing came as congressional advocates of stricter campaign finance rules, including a ban on "soft money" contributions to parties, renewed their drive to force a vote on the legislation before Congress's August recess. But as House members began returning from their week-long Memorial Day break, they remained 16 signatures short of the 218 required for a "discharge petition" to bypass House leaders and force a prompt vote.

So far, 196 Democrats and six Republicans have signed the petition. Speaker J. Dennis Hastert (R-Ill.) has promised a vote in September, but the bill's backers argue that this would be too late to avert another successful filibuster to kill the bill in the Senate.

CAPTION: Sen. Mitch McConnell said campaign contribution limits have been overtaken by inflation.