Donald Trump and Dick Cheney have not always gotten along. On the campaign trail, Trump repeatedly trashed the Iraq War, for which Cheney served as an irrepressible cheerleader, while the former vice president panned Trump’s proposed ban on Muslims and was conspicuously absent from the Republican National Convention. But suddenly, Cheney has emerged as a central player in the confirmation drama surrounding the selection of ExxonMobil C.E.O. Rex Tillerson as secretary of state, turning him into an unexpected Trump ally as the president-elect moves to shore up support for his controversial nominee.

Cheney’s machinations, unsurprisingly, have turned to __Marco Rubio. At the beginning of the week, Rubio joined the ranks of senators John McCain and Lindsey Graham by indicating that he might break with the G.O.P. over Tillerson’s controversial ties to the Russian government and President Vladimir Putin. “Being a ‘friend of Vladimir’ is not an attribute I am hoping for from a #SecretaryOfState,” Rubio tweeted on Sunday, and in a statement asserted that he had “serious concerns” about the appointment.

Rubio’s vote could prove decisive. With an edge of 52 to 48 seats in the Senate, McCain, Graham and Rubio would be enough to block Tillerson, assuming Democrats also formed a unified front in opposition of the oil executive. But of the trio, Rubio is in a uniquely powerful position. Tillerson’s confirmation will begin in the Senate Committee on Foreign Relations, where Republicans control just 10 seats to Democrats’ nine, meaning that Rubio has the power to kill the nomination before it even reaches the Senate floor.

With this in mind, it’s unsurprising that Cheney—who characterized Tillerson as an “inspired choice”—has reached out to the Florida senator to sway his vote, as The Washington Post reports. But while Cheney did vote for Trump, his demonstrated allegiance to Tillerson likely extends beyond doing a favor for the president-elect. As the former Chairman and C.E.O. of Halliburton, an engineering and construction company, Cheney has close ties to Exxon and to Tillerson, who has overseen deals with Halliburton in Iraq.

Nor is Cheney the only Republican whose financial ties to Exxon may be informing his lobbying efforts. As the Post has reported, Tillerson’s name was first floated by thee George W. Bush administration alumni, Condoleezza Rice, Stephen Hadley, and Robert Gates, whose international consulting form—Rice Hadley Gates—happens to represent ExxonMobil as one of its biggest clients. Rice, a former secretary of state. reportedly talked up Tillerson to vice-president-elect Mike Pence, while Gates, a former C.I.A. director and defense secretary, recommended the C.E.O. directly to Trump. Trump was “intrigued”, and nominated Tillerson two weeks later.