An Elizabeth Warren fund-raising email has reached us outlining the pact she has struck with Scott Brown, her opponent in the senatorial race at Massachusetts. The deal is, she says, “aimed at keeping advertising by Wall Street, Karl Rove, and other big players out of our campaign for the United States Senate.” James Taranto of the Wall Street Journal sent out yesterday a terrific dispatch about it, calling the pact an “appalling agreement” and a “conspiracy of silence.” It appears to be an effort to block banks, labor unions, religious groups, environmentalists, and others with an interest in the election from having their say.

The question that nags at us is what is the correct move for such groups. The way the Brown-Warren Pact works is that, as Mrs. Warren puts it in her fund-raising wire, if “an independent third party group spends money on TV, radio, or online supporting a candidate, that candidate has agreed to pay 50% of the cost of airing that ad to a charity of the other candidate’s choice.” The theory of the scheme seems to be that if, say, Karl Rove wants to spend money to support Senator Brown, Mr. Brown’s campaign would have to pay half the amount to charity, even if Mr. Rove’s spending is independent of Mr. Brown’s campaign.

Now, Karl Rove is smarter than we are — we make that stipulation with genuine admiration — but our instinct is that the right move would be for him to announce that he will spend a fortune in the Massachusetts race supporting Scott Brown and attacking Mrs. Warren. And then to go ahead and spend that fortune. It would be a service to the people of Massachusetts, not to mention, given the reach of a senator’s impact, the  people of the rest of the country, who have such an enormous stake in the Massachusetts race.

True, it would also saddle the Brown campaign with a debt to the charities Mrs. Warren names. And she or her “People’s Campaign” may pick the League for Unwed Communists or the North Korea Children’s Social Welfare Fund. The key point is that to make the advertising buy vastly more than Scott Brown or his campaign could ever possibly pay. That would force the Unwed Communists or the North Korean Children’s Welfare Fund — both, if they exist at all, no doubt fronts for the Party — to try to collect. Mrs. Warren will be tied up for years in court and might net the charities one used pickup truck.

Of course, another way for Mr. Rove to handle the situation would be to spend millions on television ads in support of Mrs. Warren. It’ll be hard thinking of reasons to vote for her, but one could come up with something (maybe “we need more lawyers in Washington”). Mr. Rove could put his own smiling face — and Mr. Brown’s — on the ads just to underline how important Mrs. Warren’s victory is to him. In any event, Mrs. Warren’s campaign will have to disgorge half that fortune to charities that Scott Brown favors, like the National Pickup Truck Museum and the Massachusetts Hockey Puck Parade.

Meantime, Mrs. Warren’s fundraising letter wants her supporters to sign a  “People’s Pledge,” the signing page for which contains a big red button inviting readers to “donate now.” It seems Mrs. Warren doesn’t want the financial costs of getting her message out to be picked up by corporations and wealthy organizations. She wants the costs to be laid directly on her hard-put-upon, out-of-work followers. Why would a Republican like Senator Brown sign such a pledge? Well, the last part of the last sentence of the Washington Post story on this plot notes that Mrs. Warren “has benefited more than Brown from outside spending in Massachusetts.” Maybe the senator isn’t such a dummy after all.