Yes, more so. As it was, I think it was already extremely plausible; it's definitely the hobby horse I'm known for at this point, but that's because I think it's underestimated despite the copious evidence I've turned up for it.
Have Polk do better at winning (Tennessee, New Jersey and Ohio are won) and have higher coattails in the Congressional races. That will prevent the Whig control over the House later on, and help to undermine the Calhoun faction in the South.
I was relying on the "everything that happens afterward" part.
Presumably that would be the ASB intervention, in Long survives the assassination attempt and then is able to run and win the 1936 election.
1844, with James K Polk choosing someone other than Nicholas Trist as the peace envoy and thus the U.S. annexes all of Mexico. Or 1936, with Huey Long.