The long-running money primary for the 2008 election now has candidates on both sides who have accepted money from dubious sources. Usually, these things come to light when one candidate zings another on a TV debate. Not so this time, reports the Los Angeles Times, which finds that donors to Sens. Hillary Clinton and John McCain have had brushes with the IRS over off-shore tax avoidance schemes.

Haim Saban, who now has a majority stake in Univision, has been a strong supporter of the New York senator’s campaign, as he was of her husband’s campaigns. The Wyly brothers, Sam and Charles, own a host of businesses including software outfits and Michael’s craft stores, and have given money to Republicans as far back as Richard Nixon. George W. Bush has also benfited from their largesse. Despite their political differences all three have used off-shore trusts to shelter income from the IRS.

Saban was trying to save a $300 million capital gains payment, he has now agreed to make. The Wylys became star attractions at a recent Senate investigation into tax avoidance and evasion. The Wylys are still defending their transactions. The stark fact is, though, that money is so important in getting organization in the states that will decide the primaries that few candidates can afford to turn back large donations from these kinds of donors. All they can hope is that the details of who gave to whom gets lost in the early rounds of speechifying and hand-shaking.