“I’m sure there are people who are unhappy with what I did on immigration and will never be supportive of me again,” Rubio said in an interview in the Capitol last week. “But by and large, I think if you look at my approval ratings in different metrics that are out there, I feel like many of my supporters maybe disagreed with me on immigration — and disagreed strongly — but they understand that I’ve been involved in other issues that are important for the country.”

That includes the growing crisis in Ukraine. While his outspokenness on Ukraine could play well with the hawkish wing of his party, it could turn off the GOP’s libertarian faction that is growing more influential. Rubio’s effort to regain conservatives’ trust will be measured on Thursday, when he addresses the annual gathering of the Conservative Political Action Conference in Washington.

“I believe people will give him on one issue quite a bit of room,” said Sen. Chuck Grassley, the influential Iowa Republican, when asked about the fallout for Rubio’s stance on immigration. “He’s already eight months away from what he did on immigration, and he’s taken on so many other issues to cloud that whole issue.”