UnitedHealth Group (NYSE:UNH) had a robust quarter. Even as unemployment drove membership rolls lower, the company topped analyst estimates by keeping costs down. Alas, none of this really matters much.

The medium-term future of UnitedHealth won't be dictated by management; it's in the hands of politicians in Washington. And there are a lot of politicians who aren't very fond of UnitedHealth, Humana, Cigna, Aetna (NYSE:AET), and the rest of the industry.

Sure, a single-payer system that puts insurers completely out of business is completely off the table, and a competing public plan seems unlikely at this point, but there's still plenty for investors to worry about. My biggest fear for insurers is that the government will require them to take in sick people without a strong enough incentive for healthy people to get insured as well. That could lead to skyrocketing insurance premiums -- someone has to pay for the sick people -- which wouldn't exactly help insurers' image, and could price some of their customers out of the market.

Just like Bank of America (NYSE:BAC), Citigroup (NYSE:C), AIG (NYSE:AIG), General Motors, Fannie Mae (NYSE:FNM) and Freddie Mac (NYSE:FRE) have been, health insurers are at the whim of the government. With that fear comes potential to make a lot of money if things go their way -- B of A is more than 500% off its 52-week low -- but you've got to guess which way the government will be swayed.

That doesn't sound like investing to me.

Even if you assume there'll be a giant stalemate, and we'll see business as usual, UnitedHealth may not be a bargain, even though it's trading at just 8.2 times this year's expected earnings. A quick turnaround doesn't look imminent; the company expects earnings to drop next year to $2.90-$3.10 per share, from around $3.15 per share this year.

That doesn't sound like a growth industry to me.