“Being ‘poor’ in Congress is like being ‘broke’ at Harvard Business School,” Ari Melber incisively wrote yesterday. The context: Jim DeMint, one of the poorest U.S. Senators, just announced he was quitting two years into his six-year term to take the helm of the Heritage Foundation, a leviathan in the D.C. think-tank world.

We don’t know DeMint’s new compensation, but we know from the non-profit’s 990 forms that DeMint’s predecessor, outgoing president Ed Feulner, earned more than a million dollars last year.

Melber’s tweet reflected that this is the norm: leave Congress, where you earn about $140,000 and have to keep two homes, and you’re nearly guaranteed a high-paying job in D.C. afterwards.

Most lawmakers who take this route do lobbying or something like it: consulting at a lobbying firm, advising a hedge fund, or being the public face for government-dependent companies.

So I am pleased to see DeMint, who in the Senate was a leading opponent of cronyism and corporate welfare, didn’t go the corporate cashout angle. He is taking a slightly smaller payday than he could otherwise (a two-term Senator who sat on Commerce could pocket about $1 million for a job where he didn’t do anything, and he could get very rich at a job where he actually worked [see Trent Lott and John Breaux]). Some people, especially liberals, will attack him just for making lots of money. But there’s nothing wrong with making lots of money. What matters is what retired “public servants” do with their knowledge and experience.

At Heritage, DeMint will put his knowledge and experience to work for a cause, rather than for a special interest. Again, if you’re a liberal, you might not distinguish between conservatism and corporatism, but that’s only because you’re not paying attention, or you’re blinded by ideology. That’s worth something.

More important than the savoriness of what a lawmaker does after he leaves is the appearance of propriety and possibility for abuse of power when they are in office. When you look at a Senator who cashes out to K Street, Wall Street, or a giant industry group, you have to wonder, Did he play ball with that industry in order to be more hirable? Or even worse, Did he give them some government favor in exchange for getting this job?

If DeMint was “doing favors” for Heritage — a non-profit group — what form would that take? Basically, being a conservative. Basically, cashing out to a cause is far better than cashing out to a special interest.

Here’s politician who cashed out in way better than lobbying: Sarah Palin. Maybe it’s embarrassing for a former governor to do a reality show and charge so much for speeches, but at the worst, she’s a publicity hound. She’s not putting her public service to work for special interests.

But DeMint and Palin have more in common: They both quit early.

Failing to serve out a full term is not exactly breach of contract, but it does count as breaking an implicit commitment. If you don’t finish your term, you had better have a very good reason. Is your wife sick? Are you going poor?

For Palin, I can’t imagine a good reason. For DeMint, here’s the reason: If he refused to be a lobbyist, he would never have another opportunity as good as running Heritage  – and that job wouldn’t be open at the end of his term in 2017.

I don’t know what I would do in his situation, but I also don’t blame the voters of South Carolina if they feel wronged.