Two years after Republican voters ended his quest for the presidential nomination, John McCain is being urged to try again this time as a Democrat. A pair of liberal writers, having decided that none of the Democratic aspirants makes their hearts go pitter-pat, have gone into print arguing that the best bet to beat President Bush in 2004 is the Arizona senator who lost to him in the primaries last time around.

That proposition is implausible on its face, and it grows truly absurd on examination. Nonetheless, two of the publications most proud of their reputation as bastions of liberal thought have published almost simultaneous feature articles boosting McCain.

Joshua Green in the May issue of Washington Monthly and Jonathan Chait in the April 29 New Republic make strikingly similar arguments for McCain, a lifelong Republican, to switch parties and run under the Democratic banner.

They are enchanted by the McCain persona, as so many other journalists were when he was riding the “Straight Talk Express” into battle against Bush in New Hampshire, South Carolina, Michigan, California and other states until the GOP establishment threw him back.

The adulation is also visible in a new book by veteran Washington journalist Elizabeth Drew, “Citizen McCain.” In addition to a detailed recounting of last year’s successful battle for campaign finance reform (viewed almost entirely from McCain’s perspective), Drew suggests that it was McCain, more than the president, who steadied the nerves of the American people in the aftermath of 9/11, providing the necessary strength and reassurance. I could have sworn it was Bush on the rostrum of the House of Representatives, but my memory is often faulty.

Still, it does amaze me to see this lively, gutsy and quirky man, one of the most useful members of the Senate, who has never given anyone reason to doubt his fidelity to his principles or his party, become the target of an attempted political kidnapping by prematurely pessimistic liberals.

Green and Chait argue two propositions first, that McCain should become a Democrat, and second, that the Democrats should pick him over all the White House aspirants who have been laboring in the vineyard for many years.

He’s never going to make the White House as a Republican, they say, and on that they are assuredly right. The party has moved to the right, they say, while he has moved to the left. Look at the co-sponsors of his major bills: Russ Feingold on campaign finance, John Edwards and Ted Kennedy on patients’ rights, Joe Lieberman on the gun show loophole, John Kerry on fuel-efficiency standards and Evan Bayh on national service.

They fail to note that Kennedy, for one, always seeks Republican co-sponsors for his bills or maybe they think Kennedy should join the GOP, since the Democrats won’t nominate him.

They acknowledge that some of McCain’s stands what Green refers to delicately as his “relative conservatism” might go down hard with traditional Democrats. But they argue that Democrats will swallow their doubts because, as Chait puts it, “he may be the only candidate who could beat Bush.”

It is astonishing to me that people who admire McCain for his character would think his politics so malleable. This is a man who campaigned in California in 2000 as “a proud conservative with a strong conservative record in the tradition of Ronald Reagan.” Do they think he can campaign four years later on the legacy of the New Deal, the Fair Deal, the New Frontier and the Great Society?

Those who really know McCain know better. Mark Salter, a senior staffer who shared the writing duties on McCain’s last book and drafts most of his speeches, said to me, “He supports stem cell and fetal tissue research, but he is pro-life. The minute he says, ‘I was pro-life, but not any longer,’ it’s over.” In other words, his credibility his greatest asset would be gone.

And barely pausing for breath, Salter lists other key issues on which McCain disagrees with most Democratic activists: “He is an unrestrained free-trader. He supports school vouchers. He favors a national missile defense. He thinks it is a good idea for people to have an option on Social Security for private investment accounts. He has cast right-to-work votes. He has opposed some past minimum wage increases. And he positively hates the new farm bill.”

I asked Salter what McCain thought of suggestions he switch parties to run for president. “He just laughed,” Salter said. A good man’s sensible response to a laughable notion.

David Broder is a columnist for Washington Post Writers Group.