Sen. Marco Rubio’s support among Republican voters has dropped 15 points since February, shortly after he took a high-profile role in advocating comprehensive immigration reform, according to a new Rasmussen poll.

The survey, of 1,000 likely voters conducted June 20-21, found that 58 percent of Republicans nationwide view Rubio favorably. That is down from Rubio’s 73 percent favorable rating among Republicans in mid-February. Rubio introduced the Gang of Eight immigration initiative in the last days of January.