April 24 is Pennsylvania primary day, and it could have huge consequences for both Mitt Romney and Rick Santorum. According to the Democratic polling firm Public Policy Polling, Romney now leads Santorum 42 to 37 percent. And then there’s this key information:

Romney’s made huge in roads with the groups that have tended to fuel Santorum’s success. What was a 37 point lead for Santorum with Evangelicals is now only 10 points at 44-34. What was a 32 point advantage for him with Tea Party voters is now only 6 at 41-35. And in the greatest sign that conservatives are starting to really around Romney a little bit, what was a 51 point deficit for him with ‘very conservative’ voters is now only 11 points at 44-33.

It’s been clear for weeks that the Obama campaign believes they will face Romney in the general election, and now the math appears to be catching up to that conclusion.