There were many disagreements during Thursday night’s GOP presidential debate in Detroit, but frontrunners Donald Trump and Ted Cruz agreed on one thing: Money buys influence in politics.

Cruz challenged Trump for making campaign contributions to Democrats. Trump responded by saying that he has “supported Democrats, and I’ve supported Republicans. And as a businessman, I owed that to my company, to my family, to my workers, to everybody to get along.”

His clear implication was that financial support to politicians helped him advance his business interests.

Cruz allowed that making campaign contributions as a way of buying influence was understandable:

Donald mentioned a moment ago that he was just doing business when he was writing checks to liberal Democrats. But that’s not, in fact, the checks he was writing. Listen, we could all understand if you write a check to a city commission because you’re looking for a zoning waiver on building a building. That may be corrupt, but you could understand real estate developers doing that.

Cruz instead accused Trump of making the contributions as an expression of his political support — which, of course, is the only historically acceptable reason to give money to campaigns:

That’s not what Donald Trump did. Donald Trump supported Jimmy Carter over Ronald Reagan. Donald supported John Kerry over George W. Bush. If you don’t like Obamacare, Donald Trump funded Harry Reid and Nancy Pelosi taking over Congress to pass Obamacare.

Trump objected that his contributions were not political in nature, but purely transactional:

Actually, it was for business. It was. It was. It was for business. I pride myself, including outside of the United States. I’m doing almost 120 deals outside of the — which I hope to be able to stop very soon and let my children handle it — but we’re doing many, many deals outside of the United States.

I support politicians. In 2008, I supported Hillary Clinton. I supported many other people, by the way. And that was because of the fact that I’m in business.

Neither the moderators nor the other candidates objected to this characterization of political giving. In a political campaign full of smoke and mirrors, it was a rare moment of brazen honesty about the corruption in our system.

Related: