I reckon had Robert La Follette have ran in 1912 as an Independent he would have taken less votes from William Howard Taft. Thus making the election much closer than it was in RL. I believe La Follette would have taken Wisconsin and possibly South Dakota.
LaFollette would have polled far fewer PVs overall than TR, but I think a lot of them would have then gone to Wilson, not Taft. Taft would have carried more states than he did IRL, but he and LaFollette combined would have won fewer states than Roosevelt did, so Wilson would have had a larger majority of the EV.