WASHINGTON » Periods of intense partisanship and turmoil occasionally lead to a smattering of congressional party-switching. But changing affiliation is no guarantee of political survival. Just ask ex-Rep. Michael P. Forbes of New York.

Before the recent decision by Rep. Parker Griffith of Alabama to change his congressional jersey, Forbes had been the last House member to abandon the majority for the minority. But back in 1999, Forbes, a three-term lawmaker, went the opposite direction of Griffith, sliding from the Republican column to the smaller Democratic side, saying his party had become too narrow and intolerant.

“;A lot of people at the time thought something was clearly wrong with me,”; Forbes, now a lobbyist, said in an interview, recounting how he gave up a desirable slot on the Appropriations Committee. “;On the political landscape, a lot of people just thought it was a dumb move.”;

Not only did Forbes become the bane of Republicans overnight, but there were plenty of Democrats who did not want him either. Republicans, eager to discourage other potential defectors, ganged up on him in the Democratic primary in 2000. He lost by a handful of votes to a retired school librarian, who then lost the general election.

Forbes' experience is not uncommon. About one-third of the 16 U.S. representatives who switched since 1980 lost the next election for either their House seat or another office. Others, however, have become influential and admired members of their new party.

Party-switchers have fared better in the Senate, though Arlen Specter of Pennsylvania, who defected to the Democrats after his vote for the economic stimulus bill proved unpopular back home, is facing re-election challenges from both the right and the left.

Griffith, the first-term lawmaker who signed on with Republicans last month, can probably relate to Forbes at the moment. He has outraged Democratic colleagues who cannot fathom that he jumped ship less than a year into his first term after the party invested in his initial election. Democrats are casting about for a top-tier opponent for their ex-candidate.

At the same time, some Republicans in Alabama are not eager to have Griffith as a new member of their club, saying his regular votes for Democratic initiatives—not to mention his supporting Nancy Pelosi for speaker at the start of 2009—show that he is not conservative enough at a time when the party is looking for true-blue Republicans.

Party strategists in Washington say they expect Griffith to hang on in his district and become a dependable Republican vote, even though he is taking a pounding at the moment. They say that his decision to abandon the majority party shows just how frustrated conservative and centrist Democrats are with their party's direction. They hope to persuade a few more to cross the aisle.

“;Nancy Pelosi's decision to move her extreme agenda against the will of the American people has alienated a number of members within her own caucus to the point they are opting for retirement or even willing to switch parties,”; said Ken Spain, a spokesman for the National Republican Congressional Committee.

If they are able to bag another Democrat or two, Republicans could claim a sense of momentum as they enter 2010, a welcome shift for them after losing the last two special House elections. And they have made some interesting overtures, with Sen. John McCain of Arizona reaching out to Rep. Christopher Carney of Pennsylvania, a Democrat and fellow naval officer, to ask him to consider a change.

But party-switching is a delicate and typically secretive process, and the first move usually has to come from the switcher. Republicans risk losing potential conquests if they get too aggressive and public. And despite obvious unrest among more-conservative Democrats about the difficult environment lying ahead in the midterm elections, only the most optimistic Republicans anticipate a wave of defections.

But Griffith's move, which came after a poll showed him in re-election trouble, certainly caught the attention of Democrats. They moved quickly to take the temperature of other House Democrats considered potential Republican targets, including Reps. Bobby Bright, Griffith's fellow Alabamian; Travis W. Childers of Mississippi; and Walt Minnick of Idaho. Along with Carney, the Democrats indicated they were not contemplating a change.

Rep. Chris Van Hollen of Maryland, chairman of the Democratic Congressional Campaign Committee, said he believed that Griffith could have won re-election as a Democrat and that the lawmaker miscalculated. He does not anticipate more desertions.

“;People don't like finger-to-the-wind politicians,”; Van Hollen said. “;I am very confident that we are not going to see any more people switching parties.”;

Forbes remains comfortable with his move and noted that even some Republican friends who ostracized him at the time eventually came around. But his advice on party-switching is to make the decision based on true philosophical reasons, not political expediency.

“;I thought about it for more than a year, and intensely for more than six months,”; Forbes said, recalling his deliberations. “;And I was probably naive to believe some factions were not going to be as hostile as they ended up being. It was rough.”;But my life has gone in a direction now that basically confirms every day that it was the right decision for me.”;