I think it's closer to baseball than people realize, but you're right, it's not coming close to football or basketball anytime soon. And the reason I mention that about baseball is based on some conversations on Mike and Mike this morning. They were talking to Tony Clark, who, as the head of the MLBPA, called baseball a "regional sport" and that stance floored Greenberg. They also talked at length about how, back in the day, the most famous athletes in America were all baseball players. Now, it's football and basketball, and baseball players who become true household names and superstars are becoming more and more rare.
Look at some recent national polls...ESPN recently conducted one about the most popular athletes in America, and while I can't find a direct link to the poll I found this:
http://nesn.com/2014/06/espn-poll-tom-brady-nations-5th-favorite-athlete-peyton-manning-2nd-photo/ ...which shows that the only baseball player more popular than Lionel Messi in America is Derek Jeter. The same poll shows that international soccer (not MLS) is more popular in the US than college hoops, NASCAR, and the NHL. That one surprises me a bit.
This also shows that MLS is as popular with 12-17 year olds as MLB, the first time that's ever been the case:
http://www.espnfc.com/major-league-...hes-mlb-in-popularity-with-kidssays-espn-poll