With Scott Walker’s recent departure from the presidential race, Marco Rubio has been leaning in to his role as new Koch favorite. Rubio’s positions on ending the Ex-Im Bank, blocking a minimum wage increase, and pushing a tax plan that would give tax breaks to the top one percent mean that the Florida senator has been in the running for the Kochs’ invisible primary since its start.

In the past month, he’s taken on even more extracurricular Koch activities to impress the brothers. Earlier this week, the candidate held a town hall in Nevada with the Koch front group, the LIBRE Initiative. And next week he’ll do a town hall with another Koch front group, Concerned Veterans for America.

Now, it seems that the so-called “frugal” campaign that Rubio is running has been spending big bucks to get an in with the Kochs. According to Politico, the campaign “spent about $271,000 on private jet flights — including one from Koch Industries Aviation, owned by the billionaire conservative financier Koch brothers.”

After raising an underwhelming $6 million in the third quarter, Rubio is taking every opportunity to schmooze with the billionaires in hopes of getting a piece of the $900 million pie. Whether he’ll win out over the rest of the field in the end is hard to say, but one thing is for sure, whoever the GOP candidate is — they’ll belong to the Kochs.