SENATE MINORITY Leader Bob Dole has applied for federal funds to help finance his presidential campaign. At the same time he continues to lead a Republican filibuster against the use of public funds to help finance Senate campaigns. The filibuster arguments are all, of course, highly principled. The Senate doesn't need its own welfare program; to subsidize itself while cutting subsidies for others would be wrong. To flood this critical part of the democratic process with public funds and impose spending limits in return, as is proposed, would also be to stifle healthy competition and expression. And do you wonder why these same firm principles don't seem to apply to the presidential campaign? At the presidential level, Mr. Dole plainly thinks the public funds, which other candidates are also taking, may help him win. In the Senate, however, the Republicans, who are the more sophisticated fund-raisers, think their party would be hurt by the combination of public financing and spending limits.

They're wrong, we believe, and shortsighted as well. The excess of the present system of congressional campaign finance will in the long run stain those who support it. The Republicans say that the enormous amounts now raised and spent in each election cycle are proof of vitality, signs of broad political participation and a great leveling device, in that extra money is how challengers get better known. Our contrary sense is that the price of office has been bid so high as to deter many more challengers than the present system helps. The average Senate victor spent a little over $3 million last election; a candidate for a contested seat can expect to spend much more. The figures are quadruple what they were 10 years ago; to accumulate what it takes to run for reelection, the average senator must now raise $10,000 a week every week of his entire six-year term. At some point in a process such as this, a candidate is no longer running for office so much as trying to buy it. The amounts are not just obscene; they are insane.

The bill before the Senate seeks to limit them. The Supreme Court has said that to satisfy the First Amendment, spending limits must be voluntary; as a practical matter, this means they can only be enforced in return for federal funds. But Republicans object to federal funding; the sponsoring Democrats have therefore steadily reduced the role of public funds in their proposal, until now it has reached the point that the public money would be only an insurance policy. A candidate could get such money only if he abided by a spending limit which his opponent then surpassed.

Five times the Democrats have tried in the past two months to invoke cloture on the bill, and five times they have lost. But Majority Leader Robert Byrd has not taken the bill down; he is said to be determined to make the Republicans keep voting on it and, to the extent he can, hang those votes around their neck. He's right to do it. The Republicans are on the wrong side of this issue; Mr. Dole should lead them to a better plac