FACTBOX: Specter often breaks ranks with Republicans

(Reuters) - Since he was first elected to the U.S. Senate in 1980, Arlen Specter, a moderate, has often broken ranks with fellow Republicans.

On Tuesday, Specter switched to the Democratic Party, saying Republicans had drifted too far to the political right and acknowledging the move would give him a better chance to win reelection next year in Pennsylvania.

Here are some facts about Specter's Senate record:

* He was one of only three Republicans who voted in February for President Obama's $787 billion economic stimulus package, a move that riled conservatives in his home state.

* He joined Republicans in opposing Obama's $3.5 trillion budget plan, which critics complained had too much spending and too much taxes.

* He dropped his support this year for a bill opposed by business and backed by organized labor and Democrats that would make it easier for workers to unionize.

* Specter has been seen as a possible supporter of Obama's drive for a bill to reduce industrial emissions and curb global warming.

* As a member of the Judiciary Committee, he helped defeat the Supreme Court nomination of Robert Bork during the Reagan administration, helped win confirmation to the high court of Clarence Thomas during the administration of the first President George Bush and helped confirm Chief Justice John Roberts during the administration of the second President George Bush.

* Specter helped defeat President Bill Clinton's massive health care plan but also helped acquit Clinton on impeachment charges in a 1999 Senate trial stemming from the president's affair with an intern.

* Specter has been a leading advocate for stem cell research, which put him at odds with many in his party, including former President George Bush.

(Reporting by Thomas Ferraro and Richard Cowan)