Rep. Steve Buyer (R-IN) sat down for an interview with CBS Evening News about his charity, but struggled to answer basic questions about the Frontier Foundation, which collects big donations from industry sources trying to influence Buyer but gives out no money for its putative mission of supporting Indiana students.

Buyer abruptly ended the interview with CBS, which aired last night, literally rushing out of his seat to make a meeting.

Among the questions he couldn't answer: why the foundation, which as recently as last month shared space with Buyer's campaign office in Monticello, Indiana, no longer has a physical address

"I was so focused on making sure that we were legal, that I probably didn't pay as close attention as I should have on, quote, appearances," the congressman said.

Asked by reporter Sharyl Attkisson about legislation he has introduced or supported that helps donors to Frontier, Buyer says at one point: "Trying to match up legislation like that is erroneous. You shouldn't do that Sharyl. I think that it's, I think it's wrong."

Check out one key exchange, where CBS asks Buyer about the fact that all of the donations to the foundation come from lobbyists and corporate sources with interests that Buyer has supported:

Attkisson: From what I can tell, all of the donors have interests before committees that you sit on in Congress.

Buyer: Well, the committees in which were, uh, the committees, the corporations in which provided support, like I said, were those original companies. Please do not assume that if a company contributes to the foundation that that's somehow some type of influence upon what I'm about to do.

CBS also uncovers the fact that the $25,000 in seed money that started the foundation came from PhRMA. We've previously noted that PhRMA is the single biggest donor to the foundation, giving at least $200,000 over the past several years. TPMmuckraker reported late last month that PhRMA also hired Buyer's son -- who is on the board of the foundation -- to work at its Washington headquarters. Buyer is a member of the House Energy Subcommittee on Health, which regulates drugs.

If you want to know more about how Buyer's foundation has supported his golf habit, we have the full rundown here. It's also worth noting that Buyer originally denied Frontier was different than any other charity he supported, before admitting it is, in fact, his foundation.

Below is the CBS segment with Attkisson, who, to her credit, asks some tough questions.

And here's the Q&A between Buyer and Attkisson.