It’s not very often that the party out of power encourages the incumbent to seek re-election, but that’s the case in Pennsylvania.

Republican Gov. Tom Corbett’s polling numbers have sagged to the point where Democrats are excited about their opportunity but nervous he will retire, thereby allowing state Republicans to find a potentially stronger nominee.

Democrats are headed for a competitive primary between suburban Philadelphia Rep. Allyson Y. Schwartz, state Treasurer Rob McCord, wealthy businessman Tom Wolf, and others, but they should have a credible nominee.

A May 30-June 4 Quinnipiac University poll showed Corbett losing to Schwartz and McCord by 8 points to 10 points. Corbett’s job rating was 35 percent approve and 48 percent disapprove.

We’re moving the race from Pure Tossup to Tossup/Tilt Democrat in the Rothenberg Political Report/Roll Call ratings.