Wilson could have defeated either Taft or TR outright in my opinion because he talked of a “New Freedom” that thrilled the uninformed. I can see similarity between Wilson and Clinton 80 years later.
If TR had been the nominee in 1912, I postulate Wilson would’ve been defeated by an achingly close margin. How so ? Look at the California returns. Taft was not on the ballot in the general election in the state because TR secured BOTH the Progressive & Republican lines. So the race was a good indicator of what such a showdown would’ve looked like between TR and Wilson with the Socialist Eugene V. Debs performing respectably. As it was, TR won the state by nearly a tie vote, less than 200 votes, each getting 41.8%. Debs took 12% and the Prohibitionist took 3.5%.
One big difference between Wilson and Clinton is that had Perot not run Clinton likely would have defeated President Bush by a 283-255 Electoral College majority (although Bush would have a chance of also winning CT and IA and getting to 270), while the 1912 results show that Wilson would not have gotten over 231 EVs (with 266 needed for victory) had he run either against Taft or TR.