The late U.S. President Ronald Reagan is often credited with saying that Latinos are Republicans at heart, but “they just don’t know it yet.”

As businessman Donald Trump continues to dominate the headlines (and the polls) surrounding the race for the Republican presidential nomination, Sen. Marco Rubio has recently eclipsed Jeb Bush as the establishment candidate of choice. But to win the contest in early 2016, Rubio will have to walk an ideological tightrope to the nomination.

Rubio has raised massive amounts of money from establishment donors with deep pockets, but the Republican electorate is hungry for an outsider candidate like Trump or neurosurgeon Ben Carson. What’s more, Rubio’s biggest liability may be one of his only major legislative projects. In the Senate, Rubio was at the forefront of a movement to push forward immigration reform, which is deeply unpopular with most GOP primary voters.

As the son of a Cuban immigrant, Rubio is one of three minority candidates leading the crowded GOP field. Even so, his party is reluctant to engage in the kind of identity politics that would allow him to capitalize off his Latino heritage. And now that he’s denounced his own immigration reform efforts, opposes raising the minimum wage, and fought the restoration of diplomatic relations with Cuba, Rubio is struggling to gain support from Latino voters.

On everything from immigration to energy regulation, Rubio must strike a delicate balance. He must counter the extremist rhetoric of candidates like Trump without alienating Trump’s voters. And to win the White House, Rubio must avoid tacking too far to the right in the primary race.

On energy, Rubio has taken a mainstream Republican stance on most issues. The U.S. is the world’s third-largest producer of crude oil behind Russia and Saudi Arabia, and Rubio seeks to end the 40-year-old ban on U.S. oil experts. He also wants to slash the federal gas tax up up to 80%. But unlike some other Republican candidates, he’s taken a softer stance on climate change and renewable energy as well, an issue that plays well with progressive voters.

“I want to be the world leader in renewables,” Rubio says in his stump speech. “But we better also be the world leader in oil and natural gas.”

So far, Rubio has proved capable of striking a delicate balance on issues like these, a skill that worries some influential Democratic strategists.

“There is a real civil war going on between populist anti-government Republicans and the establishment conservatives, and Rubio has thus far been able to escape that divide,” said David Axelrod, Obama’s former chief strategist.

Whether he can stay on that path until the primary remains to be seen.