Senator Arlen Specter is one of only three Republicans to support the economic stimulus bill in Congress, and the latest Rasmussen Reports survey in Pennsylvania shows that his position is costing him support back home.

Just 31% of Keystone State voters say are more likely to vote for Specter because of his position on the stimulus package while 40% are less likely to do so.

(Want a free daily e-mail update? Sign up now. If it's in the news, it's in our polls).

A look inside the numbers shows the problem for Specter may be even more significant. Fifty-eight percent (58%) of Republican voters in the state are less likely to vote for Specter. Among voters not affiliated with either major party, just 27% are more likely to support the long-time incumbent while 48% are less likely to do so.

These numbers are not surprising given the partisan response to the stimulus bill itself. Nationwide, support for the stimulus legislation increased following President Obama’s nationally televised press conference earlier this week. Still, the legislation is perceived as being what Democrats want rather than a bipartisan product.

In Pennsylvania, 69% of Republicans oppose the package while 73% of Democrats favor it. Those not affiliated with either major party are evenly divided. That partisan divide places Specter in a difficult position. Even though Specter has aligned himself with the president and other Democrats on the stimulus, the Democratic Senatorial Campaign Committee has announced that the Pennsylvania Republican is one of their top targets for the 2010 election cycle.

Specter won re-election in 2004 by a 53% to 42% margin. However, he barely survived a conservative primary challenge from then-Congressman Pat Toomey. Even though he had the support of the state’s Republican establishment, Specter was able to defeat Toomey only by two points, 51% to 49%.

Overall, Pennsylvania voters support the stimulus measure by a 47% to 41% margin. Still, 52% say the legislation is at least somewhat likely to make things worse instead of better.

In December, Rasmussen Reports polling showed Specter in a tight re-election match-up against MSNBC television anchor Chris Matthews. Matthews has since indicated that he will not run for the seat.

In that December survey, 60% of Pennsylvania voters had a favorable opinion of Specter, including 20% Very Favorable. Specter was viewed unfavorably by 37% percent, including 13% who had a Very Unfavorable opinion.

Please sign up for the Rasmussen Reports daily e-mail update (it’s free)… let us keep you up to date with the latest public opinion news.

See survey questions and toplines. Crosstabs are available to Premium Members only.