Pennsylvania Senator Rick Santorum (R) retains his title as the nation's most vulnerable incumbent for Election 2006. The latest Rasmussen Reports election poll in the Keystone State shows Santorum trailing Democrat Bob Casey by 13 percentage points, 51% to 38% (see crosstabs).

For the challenger, that's slightly better than our March 29 poll which showed him leading 50% to 41%. Casey has been ahead in all seven of our Pennsylvania election polls by margins ranging from nine to twenty percentage points.

Santorum is struggling with his base, consistently earning less than 70% of the vote from Pennsylvania Republicans. He's at 65% support from the GOP in the current poll.

Casey, on the other hand, is supported by 77% of Democrats.

Just 25% of all voters have a "very favorable" opinion of Rick Santorum while 24% have a "very unfavorable" opinion of him.

For Casey, the numbers are 18% "very favorable" and 9% "very unfavorable."

By a 51% to 19% margin, Pennsylvania voters believe that tax cuts help the economy. Seventeen percent (17%) say they have no impact while 13% are not sure. A slightly majority say that tax preparation is worse than going to the dentist.

On immigration, 74% believe that the federal government should gain control of the border and enforce existing laws before considering other reforms. Sixty-one percent (61%) say that our nation's policy goal should be to welcome all immigrants legally except for national security threats, criminals, and those who intend to live off the U.S. welfare system.

Just 29% believe that children of illegal immigrants should automatically be granted U.S. citizenship.

The rolling average of the last three Rasmussen Reports Pennsylvania election polls shows Casey continuing to hold a solid lead, 50% to 39%. That's virtually unchanged from our previous 3-poll rolling average.

Crosstabs are available for Premium Members.