[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/04/28/art_arlen_specter_gi.jpg caption= "Sen. Arlen Specter was expected to face a tough primary challenge in 2010."]
WASHINGTON (CNN) - Veteran Pennsylvania Sen. Arlen Specter told colleagues Tuesday that he switched from the Republican to the Democratic Party, Sen. Harry Reid says.
The Specter party switch would give Democrats a filibuster-proof Senate majority of 60 seats if Al Franken holds his current lead in the disputed Minnesota Senate race.
"Since my election in 1980, as part of the Reagan Big Tent, the Republican Party has moved far to the right," Specter said in a statement posted by his office on PoliticsPA.com.
"Last year, more than 200,000 Republicans in Pennsylvania changed their registration to become Democrats. I now find my political philosophy more in line with Democrats than Republicans."
Specter, a five-term Senate veteran, was greeted by a loud, sustained round of applause by dozens of constituents outside his Washington office shortly after the news broke.
"I don't have to say anything to them," a smiling Specter said. "They've said it to me."
Specter was expected to face a very tough primary challenge in 2010 from former Rep. Pat Toomey, who nearly defeated Specter in the Pennsylvania GOP Senate primary in 2004.
A Quinnipiac University survey of registered Pennsylvania voters released last month showed Specter trailing the more conservative Toomey in a hypothetical primary matchup, 41 to 27 percent.
A separate Franklin & Marshall survey showed Specter leading Toomey 33 to 18 percent. Another 42 percent, however, were undecided.
More than half of the Republicans polled in the Franklin & Marshall survey said they would prefer to see someone new in the Senate.
Numerous Republicans are angry with Specter over his recent vote in support of President Obama's $787 billion stimulus plan.
Specter, one of only three GOP senators to vote for the measure, has been part of a dwindling group of GOP moderates from the northeastern part of the country.
Statement from Senate Majority Leader Harry Reid
“I have known Senator Specter for more than a quarter-century. He has always been a man of honor and integrity, and a fine public servant. Senator Specter and I have had a long dialogue about his place in an evolving Republican Party. We have not always agreed on every issue, but Senator Specter has shown a willingness to work in a bipartisan manner, put people over party, and do what is right for Pennsylvanians and all Americans. I welcome Senator Specter and his moderate voice to our diverse caucus, and to continuing our open and honest debate about the best way to make life better for the American people.”
Statement from Republican National Committee Chairman Michael Steele
“Some in the Republican Party are happy about this. I am not. Let’s be honest-Senator Specter didn’t leave the GOP based on principles of any kind. He left to further his personal political interests because he knew that he was going to lose a Republican primary due to his left-wing voting record. Republicans look forward to beating Sen. Specter in 2010, assuming the Democrats don’t do it first.”