The following is a transcript of Sen. Specter's speech at a news conference announcing his decision to join the Democratic Party:

SPECTER: 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 the Democratic Party. When the stimulus package came up for a vote, I felt that it was indispensable to vote aye in order to avoid the possibility of a 1929-type depression.

In the course of the last several months since the stimulus vote, I have traveled the state and surveyed the sentiments of the Republican Party in Pennsylvania and public opinion polls, observed other public opinion polls and have found that the prospects for winning a Republican primary are bleak.

I am not prepared to have my 29-year record in the United States Senate decided by the Pennsylvania Republican primary electorate -- not prepared to have that record decided by that jury, the Pennsylvania Republican primary electorate.

But I'm prepared today take on all comers -- all comers in a general election. And, therefore, I have decided to be a candidate for reelection in 2010 in the Democratic primary. This is a painful decision. I know that I'm disappointing many of my friends and colleagues but, frankly, I have been disappointed by some of the responses. So the disappointment runs in both directions.

I do not undertake this because of the absence of other challenging or interesting things that I could undertake outside the Senate. But I do this because there are many projects that I want to move ahead for Pennsylvania with my continuing seniority in the United States Senate. And one of the key interests I have is medical research and want to continue my work in that field.

I think it is fair and accurate to say with the increases in funding for National Institutes of Health, which I have spearheaded, have saved or prolonged many lives including my own. One item that I want to emphasize that I will not be changing my own personal independence or my own approach to individual issues. I will not be an automatic 60th vote.

I note that some of the news stories since my statement was released this morning are taking a look at the 60th vote. And I will not be an automatic 60th vote. And I would illustrate that by my position on employee's choice, also known as card check. I think it is a bad deal. I'm opposed to it and would not vote to invoke cloture. But that's only indicative of my view in that respect.

I have always agreed with John Kennedy that sometimes a party asks too much. And if the Democratic Party asks too much, I will not hesitate to disagree and vote my independent thinking and what I consider as a matter of conscience to be in the interest of the state and nation.