North Shore Congressman Mark Kirk wants Congress to expand the variety of stem cells available for scientific research. But some conservatives say the Republican is playing politics in his bid for the U.S. Senate.

Kirk says the bill would permanently authorize various types of stem cell research. Right now, that research is protected only by a presidential order, which could be overturned by a new president.

Recently, Kirk has taken hits from Democrats who say he’s too conservative for Illinois.

But he denies playing politics on stem cells.

KIRK: I am a fiscal conservative and a social moderate. And so I seek to serve in the Senate the way I’ve served in the house.

That’s no consolation to Bill Beckman, who heads the Illinois Right to Life Committee.

He says he opposes stem cell research because some of the cells come from embryos. And he says Kirk’s leaving conservatives out in the cold.

BECKMAN: It’s no different than the position of the Democratic candidate. I mean, so it’s like there’s no - there’s no choice here.

Conservatives have previously attacked Kirk for his moderate stance on abortion and the environment.