Freddie Mac is playing an unexpectedly big a role in the GOP primary -- and that's a good thing.

In the clip above from Thursday evening's GOP debate, Michele Bachmann attacks Newt Gingrich over his $1.6 million payday from Freddie Mac. By now, everyone following the campaign knows that the former House Speaker's lobbying is a liability as he seeks the nomination.

What I wonder is whether this is a special case. Influence-peddling might not be an issue if not for the financial crisis and the right's insistence on pinning the bulk of the blame on federally sponsored entities that helped inflate the housing bubble. Being tied to Freddie Mac is unique.

But maybe the Tea Party deserves credit for the tendency of people like Sarah Palin and Michele Bachmann to challenge insider cronyism and the revolving door. It would be a good thing if, going forward, politicians face greater scrutiny for how they earn their living once they leave office, and are objects of sustained derision if they're seen to profit off their time in government.

It seems as though Gingrich was careful to avoid having to actually register as a lobbyist after he left Congress. And perhaps more political players will now be careful to avoid even the appearance that they're selling influence. That's hardly going to solve the problem of the revolving door. Lots of folks leave the House or staff positions without any aspiration for higher office.

Even so, cultural shifts have to start somewhere.