DENVER - In selecting Sen. Joseph Biden as his running mate, Barack Obama gains some needed foreign policy expertise, but loses some credibility. If Washington is as bad as these two say it is, was Biden a contributor or an enabler during his six Senate terms? If 36 years in the Senate doesn't make you an "insider" and part of the problem, what does?

Presidential candidates love to run against Washington and pretend they are outsiders, even when they have been insiders. The same applies to John McCain, who has been an insider for 26 years, 24 of them in the Senate. But while McCain has been critical of some Bush administration policies - notably the initial way the Iraq War was fought with too few troops - Biden has a litany of criticism of Obama, which the McCain campaign will use to undermine whatever enhancements Biden brings to the Democratic ticket.

Last August on "The Diane Rehm Show," Biden said, "If the Democrats think we're going to be able to nominate someone who can win without that person being able to table unimpeachable credentials on national security and foreign policy, I think we're making a tragic mistake." If Democrats buy the line that Biden's foreign policy credentials as chairman of the Foreign Relations Committee make up for Obama's foreign policy deficiencies (Obama has said his opposition to the Iraq War "came from a set of experiences that come from a life of living overseas, having family overseas, being able to see the world through the eyes of people outside our borders"), aren't they making the Republicans' case for putting Dick Cheney on the GOP ticket in 2000?

While 180-degree turns are common in politics, Biden has a record of substantive criticism of Obama and of support for the Iraq War that will be difficult to explain, even in our cynical age. Presuming that Biden once held these views out of strong conviction, how does he now reverse himself without being charged with a willingness to say and do anything in order to win?

On "Meet the Press" last September, Biden attacked Obama for his vote against funding American troops in Afghanistan and Iraq: "If you tell me I've got to take away this protection for these kids in order to win the election, some things aren't worth it." This sounds similar to McCain's charge that Obama would rather lose a war in order to win an election.

Obama has said he would meet unconditionally with dictators, though he subsequently qualified that pledge by saying there must be certain unspecified advance "preparations." Last year at the National Press Club in Washington, Biden criticized Obama's initial statement saying, "Would I make a blanket commitment to meet unconditionally with the leaders of these countries within the first year I was elected president? Absolutely, positively no."

Obama has said that Saddam Hussein "poses no imminent and direct threat to the United States, or to its neighbors." Biden thought otherwise: "This is a guy who's used weapons of mass destructions. This is a guy who has destabilized the whole neighborhood. This is a guy who in a war with Iranians, over 800,000 people on both sides were killed. This is a guy who is an extreme danger to the world. And this is a guy who is in every way possible seeking weapons of mass destruction. That case, in and of itself, ought to be sufficient." ("Meet the Press," Aug. 4, 2002)

The McCain campaign can revisit quotes other than those of Obama and Biden. It has produced a new ad featuring Hillary Clinton, which recalls some of her criticisms of Obama and "empathizes" with her for not being chosen by Obama as his running mate.

There's also the issue of Obama's much touted ability to reach out and compromise with Republicans. According to the National Journal, Obama has the Senate's most liberal voting record. Joe Biden was ranked third most liberal in 2007. No demonstration of compromise there.

Biden is not "change we can believe in." He is change to deceive with. Biden's toughest opponent is not John McCain and whoever he picks as his running mate. Biden's toughest opponent is himself.