FOR YEARS, former Virginia senator George Allen said that political contributions should be based on the twin principles of freedom and disclosure — the freedom to give money without limits and full disclosure of those donations. He stressed that money should be given to, and spent by, candidates, not unaccountable outside groups.

Now Mr. Allen, running to regain his old Senate seat, is singing a different song on campaign finance. It can best be summarized as: Whatever!

In swapping principle for opportunism, Mr. Allen is marching in lock step with many fellow Republicans who are profiting politically from a tsunami of television advertising paid for by secretive outside groups. Since the GOP has been more effective than Democrats at raising money through these groups, Republicans such as Mr. Allen have ditched their insistence on disclosure and embraced an anything-goes approach.

The results are stark in the Virginia Senate race, which pits Mr. Allen against another former governor, Timothy M. Kaine (D). Although Mr. Kaine’s campaign has so far raised and spent more than Mr. Allen’s, it is Mr. Allen who is the principal beneficiary of millions of dollars given by outside groups funded by unidentified donors.

Much of it has been funneled through Crossroads Grassroots Political Strategies, a conservative group led by GOP strategist Karl Rove, and the U.S. Chamber of Commerce. Together, those two groups have placed well over 6,000 television spots on Mr. Allen’s behalf, according to the Campaign Media Analysis Group, an independent monitoring outfit. The cost of those ads to date is variously estimated at $3.5 million to $7 million. By contrast, the one significant pro-Democratic group that has spent heavily (about $2.8 million so far) on Mr. Kaine’s behalf, called Majority PAC, does disclose its donors.

In the absence of disclosure, accountability goes out the window — a point Mr. Allen once made convincingly. “I’d like to see campaigns responsible for the ads and the messages they’re sending out,” he said in 2004, noting that he’d been the target of attacks by outside groups in his first race for the Senate, in 2000.

Now that the tables have turned, Mr. Allen has been silent in the face of blatantly inaccurate ads attacking Mr. Kaine. One, paid for by Crossroads GPS, claims that the bipartisan budget deal backed last year by Mr. Kaine (as well as the GOP leadership in Congress) would result in draconian defense cuts and job losses in Virginia. In fact, Mr. Kaine has urged Congress to strike an agreement that would avoid deep cuts.

Mr. Allen, tailoring his views to fit his circumstances, now says that keeping deep-pocketed donors’ names secret is all right since they might otherwise be subject to intimidation. Please. Since when have Americans ceased having the courage to stand up publicly for their convictions?

In March, Mr. Kaine proposed that both campaigns agree to limit the influence of secretive outside groups, as Republican Sen. Scott Brown and his Democratic challenger, Elizabeth Warren, have done in Massachusetts. (In that case, each pledged to pay fines to charities if they were the beneficiary of advertising by outside groups.) Mr. Allen refused, calling the idea a “gimmick.” The real gimmick is Mr. Allen’s about-face on an issue where he once took a principled stand.