A prediction: The next senator from Delaware will know that global warming is real and will support a cap on carbon emissions.

That description fits the Democratic nominee Chris Coons, who is running unopposed in tomorrow’s primary, and GOP Rep. Mike Castle.

It does not fit Castle’s primary opponent, the Tea Party Express-funded Christine O’Donnell.

There is absolutely no way O’Donnell can win a Senate seat in Delaware. She is an extreme right-winger in a left-leaning state. 

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And Castle, who has already served as governor and has repeatedly won statewide as he is the state’s only congressperson, presents Republicans with a golden opportunity to pick up a currently Democratic-held seat.

Castle probably couldn’t be counted on to filibuster everything President Obama supported, but he would surely filibuster more than anyone else that could get elected in Delaware. And there is almost no chance Republicans can take control of the Senate — and fully control the legislative agenda — without winning Delaware.

But apparently because Castle was one of eight Republicans that actually voted for the House carbon cap bill, conservatives are willing to throw all that away.

His “cap-and-trade” vote wasn’t the only vote Castle took that put him at odds with conservatives. But it is literally at the top of Christine O’Donnell’s list of reasons for opposing him.

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And even if Castle fends off O’Donnell tomorrow, it will be because Delaware still has a significant population of Republican moderates. Today’s poll of the race shows that O’Donnell has the support of 62 percent of the state’s conservatives

In other words, if it was up to Delaware’s conservatives, they would put rejection of climate science over conservative control of the Senate agenda.

Prominent conservative activist Erick Erickson has said this bluntly: “I would rather 50 seats without Mike Castle than 51 seats with Mike Castle.”

Already, conservatives chose to roll the dice in Alaska in part because of global warming. 

Incumbent GOP Sen. Lisa Murkowski had no chance of losing her seat in a general election, and she has been a reliable “No” vote on the president’s priorities.

She didn’t back any Democratic carbon cap legislation. She even sponsored legislation to prevent the EPA from regulating greenhouse gases

But because she had the temerity to acknowledge global warming is real, met with the president to discuss compromises, and has sponsored carbon cap legislation previously, Joe Miller made her climate record “Exhibit A” in his successful primary challenge.

Miller may still win the general election — Alaska politics is far more unpredictable than Delaware politics. 

But it is indisputable that conservatives took a safe Republican seat in Alaska and made it competitive for Democrats, in part because of their irrational inability to accept climate science.

This is the nightmare that GOP Sen. Lindsey Graham (S.C.) said he wanted to avoid back in October 2009 when he struck a preliminary climate compromise with Sen. John Kerry (D-Mass.). Speaking to a group of angry South Carolina conservatives right after the climate announcement, Graham said: “I’m going to grow this party. I’m not going to let it be hijacked by Ron Paul. I’m going to find people in Maine, Delaware, Illinois, other places that can win as Republicans, and I’m going to go up, and we’re going to move this party, and this country forward, and if you don’t like it, you can leave.”

Since then, Graham bailed on the climate talks. Climate science denial is running rampant on the right. And that’s making it harder for Republicans to build a broad governing coalition.

Originally posted at OurFuture.org