Bob Shrum is a winner. Any Democratic candidate worth his salt wants Shrum on his or her team. Al Gore wanted him in 2000 and got him. John Edwards wanted him, and got him for 2003, but when Shrum wanted too much control, Edwards sent him packing to John Kerry‘s camp. And look who’s had the last laugh.

No one doubts that Kerry isn’t thanking his lucky stars that Shrum is on his team, but wherever Shrum goes, controversy seems to follow. The Edwards divorce wasn’t too messy, just enough to alienate some of Edwards’ longtime campaign aides.

Now Shrum seems to have done it again. On Friday, the Kerry campaign announced that Jim Margolis, its media buyer and, along with Shrum, one of the campaign’s TV and radio spot producers, was leaving the campaign. Margolis’s firm will continue to buy TV and radio time for the Kerry campaign, but creatively, in developing the ads’ tone and message, the job now falls exclusively to Shrum.

The split occurred, according to campaign insiders, when Margolis was presented with a new contract for the general election that essentially made Shrum his supervisor, something Margolis was not willing to live with.

“The only reason this is even a story is because it’s Shrum,” says a Kerry staffer. “This happens all the time on campaigns. People come and go, particularly now as we transition from primary to the general. All kinds of shifting is going on.”

Margolis and his firm certainly didn’t lose out in the deal. Upon joining Kerry’s campaign, he and Shrum created a firm named Riverfront Media. This company developed and produced Kerry’s radio and TV spots during the primary season, and, according to filings with the FEC, billed Kerry’s campaign more than $10.5 million.