Pennsylvania Sen. Arlen Specter's popularity has taken quite a hit since becoming a Democrat in late April, a new Franklin & Marshall poll finds. The number of Pennsylvanians who support his re-election has dropped by double digits since the college last polled voters in March.

Specter Re-election
Deserves re-election: 28 (-12 from March)
Time for change 57 (+11)
Undecided 15 (+1)

His job approval rating has fallen somewhat. But the percentage of voters who view him favorably has dropped more significantly.

Specter Job Approval: 38/59 (42/54 in March)

Fav/Unfav Rating
Specter 31/37 (down from 48/24 in March)
Rendell 42/40 (was 45/35)
Casey 32/17 (34/16)
Obama 56/27 (was 59/21)

Broken down by party, Specter's support has not surprisingly fallen most among Republicans (18, down from 49). But it has also dropped among Democrats (46, down from 57) and independents (33, down from 36).

Only one-third of Democrats supports Specter for the party's nomination in 2010, while almost half were undecided, suggesting Rep. Joe Sestak (D-Pa.) has an opening.

Democratic Primary Election Matchup
Specter 33
Sestak 13
Other 6
Undecided 48

The telephone survey of 580 adults was conducted June 16-21, and had a margin of error of +/- 4.4 percent.