Marco Rubio's problem isn't what you think it is

An average of polls taken since March 1 has Rubio’s net favorable rating at -4 points. The most recent Quinnpiac University poll shows 27 percent of registered voters giving Rubio a positive rating and 31 percent giving him a negative rating. An Associated Press-GfK survey found his favorable rating at 23 percent and his unfavorable rating at 27 percent.

It’s not clear why Rubio has fallen. The decline in his popularity among adults corresponds almost perfectly with his push for immigration reform; his largest drop occurred in June as the Senate was debating comprehensive changes to U.S. policy. I wouldn’t argue that pushing for immigration reform made Rubio unpopular, but it did give him a lot of press. FiveThirtyEight has previously said that Rubio’s ideology ranks as quite conservative. It’s possible that Americans learned more about Rubio than just his views on immigration during that period.