The Democratic party race between Specter and Sestak was considered one of the most bitter and highly watched of all the 2010 primary elections. On April 28, 2009, Specter switched to the Democratic Party after having served in the Senate as a Republican for 28 years, encouraged by Vice President Joe Biden and Pennsylvania Governor Ed Rendell, after he had voted in favor of President Barack Obama's economic stimulus plan and was faced with opposition from Pennsylvania Republicans. Although Specter claimed he switched largely because he disagreed with the increasingly conservative direction the Republican Party was heading in, he also admitted that the switch was due to his poor chances of winning a Republican primary against Toomey due to Specter's support of the Obama stimulus package . The Democratic establishment had till then encouraged Sestak, a former U.S. Navy admiral and the representative of Pennsylvania's 7th congressional district, to run in the Democratic primary. But after Specter switched parties he was largely embraced by such major Democratic figures as Obama, Biden, Rendell and Senate Majority Leader Harry Reid. The Democratic establishment now feared Sestak would harm Specter's chances in the general election and encouraged him to drop out, but Sestak refused and strongly criticized Specter's party switch as an opportunistic move aimed solely at political self-preservation.
