The Washington Post has endorsed “without ambivalence” Democrat candidate Barack Obama for president, saying that John McCain‘s “disappointing” campaign and “irresponsible” VP choice made it an easy choice.

“IT gives us no pleasure to oppose Mr. McCain. Over the years, he has been a force for principle and bipartisanship. He fought to recognize Vietnam, though some of his fellow ex-POWs vilified him for it. He stood up for humane immigration reform, though he knew Republican primary voters would punish him for it. He opposed torture and promoted campaign finance reform, a cause that Mr. Obama injured when he broke his promise to accept public financing in the general election campaign. Mr. McCain staked his career on finding a strategy for success in Iraq when just about everyone else in Washington was ready to give up. We think that he, too, might make a pretty good president.

“But the stress of a campaign can reveal some essential truths, and the picture of Mr. McCain that emerged this year is far from reassuring. To pass his party’s tax-cut litmus test, he jettisoned his commitment to balanced budgets. He hasn’t come up with a coherent agenda, and at times he has seemed rash and impulsive. And we find no way to square his professed passion for America’s national security with his choice of a running mate who, no matter what her other strengths, is not prepared to be commander in chief.”

Read the full editorial here.