The new arena in the perpetual battle over campaign finance law is the Federal Election Commission (FEC), the six-member body charged with enforcing the rules that govern the contests for Congress and the presidency.

Many of the same reformers who lobbied successfully for passage this year of the McCain-Feingold-Shays-Meehan bill, which bans unlimited "soft money" gifts to political parties and restricts so-called issue ads that target candidates, now want to overhaul the FEC.

Advocates such as Fred Wertheimer of Democracy 21, a former president of Common Cause, have begun beating the drums for turning what they call the "no-bark, no-bite" watchdog into a lean, mean agency that would, they hope, really crack down on excesses in political spending.

When Congress created the FEC almost 30 years ago, it did not want a tough cop policing its campaigns. It restricted FEC enforcement powers and saddled it with a cumbersome decision-making process. Each political party picks three of the six commissioners, through suggestions from congressional leaders to the president. Four votes are required for any action, so Republicans and Democrats have veto power over investigations they might find embarrassing.

The Republicans' choice for the latest FEC vacancy illustrates the pattern that both sides have used. He is Michael Toner, until recently the top lawyer at the Republican National Committee and before that, general counsel of George W. Bush's White House campaign.

He joins two other Republican appointees, David Mason and Bradley Smith, who are outspoken critics of the law they are supposed to enforce. On the very day it passed the House, Mason delivered a Heritage Foundation lecture arguing that key parts of the new law "are so complex, so vague or so broad as to be unworkable or unenforceable." Smith, as a law professor, wrote that even the old campaign finance law was perverse in its effects and should be scrapped.

Wertheimer and his allies would sweep all six FEC commissioners aside and give the new enforcement agency a single head -- in effect, a federal election czar. And they would also empower the agency, financially and legally, to operate as a truly independent enforcer, with a corps of presumably neutral administrative law judges handing out punishments.

The proposal has drawn broad endorsement from the same editorial pages that praised and promoted the new legislation. In both cases, the urge to purge the political system of financial corruption has led people to minimize the constitutional and practical problems involved. Commissioner Smith and his assistant, Stephen Hoersting, made the counterargument in the current Election Law Journal, and he amplified some of the points in a recent interview.

First of all, a single investigator-enforcer, operating in a highly charged political atmosphere, likely would face the same battering from his targets as Ken Starr and his predecessors in the Office of Independent Counsel endured. Like Starr, he would have no accountability to anyone for the way he exercises his vast power. There was good reason Congress let the independent prosecutor system die an unlamented death; why reinvent it in another context?

Second, Smith makes the valid point that when the current FEC has taken an aggressive stance, as it has on such questions as issue ads, political committees and coordination of campaigns, it has often been repudiated by the courts -- either for stretching the intent of Congress or for violating First Amendment rights.

But he overstates his case, I think, when he argues that "complaints about the structure of the commission are a self-deluding smoke screen masking the failure of regulatory advocates to win the political and legal battles necessary to make their vision of the law a reality."

There may be occasions when the FEC has overreached, but there are also many times when its ability to examine important cases has been frustrated by the 3-3 deadlock and the partisanship of its commissioners. Letting the political parties and key members of Congress pick the people who are supposed to monitor their campaigns is as fundamentally wrong as letting corporate CEOs be audited by accountants to whom they hand out juicy consulting contracts. Congress should not control the purse strings or the membership of the commission.

Here's a suggestion: Finance the FEC by "taxing" a fixed percentage of the receipts of the national party committees. Reduce the number of commissioners from six to five, so there can be majority decisions. And let a panel of retired federal judges submit names of prospective commissioners for appointment by the president and confirmation by the Senate.

And then let the chips fall where they may.