What do VP vetters look for when they're vetting? USA Today offers some hints:

Some issues involving potential running mates that the vetters may be mulling:

•Bayh's wife, attorney Susan Bayh, has earned $1 million a year in recent years, and nearly $2 million in stock options, through her service on 10 corporate boards, according to TheJournal-Gazette of Fort Wayne, Ind., including drug and insurance companies that have been denounced by Obama as overly powerful special interests.

Bayh spokesman Eric Kleiman said Susan Bayh has a right to her own career, and that Bayh and his aides do not allow themselves to be lobbied by representatives of the companies on whose boards his wife serves.

•Pawlenty amended his financial disclosure forms in 2003 after revealing that a businessman had paid him $4,500 per month -- a total of $60,000 -- for legal consulting while he was campaigning for governor in 2002. He had listed his consulting business, BAMCO and Associates, as an investment on the state form designed to disclose his income.

State campaign officials and local prosecutors quickly absolved him of any wrongdoing after Democrats charged the payments amounted to illegal campaign contributions. The allegations "were deemed to be without merit," Pawlenty spokesman Bob Schroeder said.

•Virginia Gov. Tim Kaine accepted a $12,000 trip to a Democratic governors meeting in Aspen, Colo., in 2006 from Barr Labs, a drug company with a large presence in his state, according to his financial disclosure statements. He also let Dominion, a Richmond-based energy company, spend $1,356 to pay his way to the NCAA basketball tournament in Indianapolis and conferences in West Virginia and New Orleans, the records show. In a state with no limits on campaign giving, he has accepted $660,000 in three years from a single donor, billionaire venture capitalist Randal Kirk, records show.

Kirk, who was given the state's Outstanding Industrialist Award in April by Kaine and the Science Museum of Virginia, told USA TODAY he does no business with the state. A Kaine spokeswoman, Delacey Skinner, said Kaine is not influenced by political contributions. The trips were within the rules, she said.

•Rep. Eric Cantor, R-Va., has been a prolific fundraiser from the lobbyists and interest groups that McCain says hold too much sway in Washington. In 2006, he donated to charity $10,000 he had received from disgraced lobbyist Jack Abramoff, who had named a sandwich after Cantor at a deli he owned, according to the Jewish newspaper The Forward. McCain helped expose the Abramoff scandal.

Rob Collins, Cantor's chief of staff, pointed out in an e-mail that Abramoff funded a group that attacked Cantor during the 2000 primary. "Cantor or his staff never met officially with or did any actions for Jack Abramoff," he said.