He’s currently polling at ~19% approval among Pennsylvania democrats, but ~80% with republicans. So if he sticks with democrat party, he has basically no chance of getting reelected. But republicans tend to do a little better in Pennsylvania (or at least, they used to, but Donny’s current term may have changed that,) so he could have a shot at winning reelection if he switches to Republican. Especially since Republicans love “I used to be a Democrat then I got some common sense” types of stories. He could ham it up for republican voters, and would likely do pretty well if he could convince them he has truly switched sides.