Artur Davis is two thirds of the way there.

The former Alabama Democratic congressman is the latest moderate to switch political parties, doing so this week while saying he may run for Congress again in Virginia, where he lives. Such an event is always read as a bad omen for the party being dumped, but Davis's departure might sting a bit more sharply, given that he's a friend, former Harvard Law classmate and early campaign supporter of President Obama, whom he criticized Wednesday in a Fox News interview.

The perceived lesson is the same, more or less, each time this happens. From Democrats-turned-Republicans like Davis and former congressman Parker Griffith, to Republicans-turned-Democrats like former senators Arlen Specter and Jim Jeffords, to newfound independents like former senator Lincoln Chafee, pundits have marked such coat-turnings as signs that parties are out of touch, having drifted too far from the center.

The process, too, is often the same. It comes in three stages, two of which Davis has now completed:

1. Lose, or Be About to Lose. Teddy Roosevelt, maybe the most prominent party-switcher of all time, left the GOP and created a progressive Bull Moose ticket in 1912 for one main reason: He lost the Republican nomination to William Howard Taft. Charlie Crist, a major party-switcher of the 2010 election cycle, was similarly forced into party independence by a primary loss, delivered by Marco Rubio in the Florida Senate primary.

Joe Lieberman, one of the best known party-switchers of the modern era, lost his Connecticut Senate primary to fellow Democrat Ned Lamont in 2006, after running alongside Al Gore for VP on the party's 2000 presidential ticket. It wasn't that Lieberman wanted out of the party; he just lost.

Arlen Specter, a centrist by tea-party-era standards, faced an intimidating primary challenge from Pat Toomey in 2009, and he likely thought it best to exit the rightward-moving GOP before Pennsylvania Republicans could reject him in favor of the tax-cutting business advocate. He wound up losing his Democratic primary to Joe Sestak, anyway. Losses all around.

Davis, operating on a delayed timeline, lost his Democratic primary for governor in 2010. A year and a half removed from Congress, he's had time to ruminate outside the public spotlight. A congressional run in Virginia, meanwhile, might be easier as a Republican.

2. Criticize Your Former Party. Whether mild-mannered rebuke or vicious screed, some form of criticism is required. When a politician switches parties, people ask why; no matter what, the answer will be critical.

When Arlen Specter left the GOP, he tactfully announced, "As the Republican Party has moved farther and farther to the right, I have found myself increasingly at odds with the Republican philosophy and more in line with the philosophy of the Democratic Party." Before he left the GOP in 2007, ousted senator Lincoln Chafee already had a track record of criticizing Republican president George W. Bush over the Iraq war. Lieberman issued his own kind of criticism in endorsing Republican candidate John McCain for president in 2008.

Artur Davis has already checked the box.

"I believed him when he said that he wanted to turn the page. I thought that he was going to be a pro-growth president, I thought that his focus at all times was going to be national unity and bringing the country together, and I saw an enormous amount of potential. What did we see? We saw a very different path,"  Davis said, criticizing Democrats for pushing massive health-care reforms through Congress despite a lack of national consensus.

3. Take a Backseat. When arriving in a new party, lawmakers can expect a warm greeting … followed quickly by a place at the back of the line.

Specter handed Senate Democrats a 60-seat supermajority in 2009, only to be stripped of his seniority and committee assignments. Although Senate Majority Leader Harry Reid had promised Specter would retain his status, the Democratic caucus voted unanimously on a set of committee assignments that treated Specter as the new kid on the block.

It's not always the case. When Sen. Jim Jeffords switched parties in 2001, Democrats had promised to make him chairman of the Environment and Public Works Committee-and they did. Lieberman, meanwhile, narrowly escaped a Democratic push to strip him of the Homeland Security and Government Affairs Committee chairmanship, after his 2008 campaigning for McCain.

But if Davis returns to Congress as a Republican, he'll get the same new-kid treatment from the House GOP conference, ranking at the bottom of GOP committee seniority lists. But with Virginia trending Republican in the 2010 midterms, at least Davis might stand a better chance of getting elected this way, should he decide to run.