Maybe it’s time for Democrats to go easy on Mitt Romney.

The usual calculations would lead to the opposite conclusion. In political campaigns, you always hope the opposing party nominates the most extreme of its possible candidates, thereby surrendering the middle of the electorate. And in this sense, Rick Perry’s candidacy is a Texas-sized gift to President Obama.

The Texas governor is an oppo researcher’s dream, an impossible blend of secession and treason and Ponzi schemes and monstrous lies. His duel for the nomination with Mitt Romney promises to be the sort of donnybrook the Republican Party hasn’t seen in many years, keeping the opposition party feuding over forced vaccinations and immigration rather than attacking Obama for his stewardship of the economy.

But what if the usual rules don’t apply in 2012? Already, upwards of seven in 10 Americans say the country is on the wrong track. What if things don’t improve – or get worse – by November 2012? In that case, voters might well be willing to pull the lever for any alternative – even a Texan who boasted about shooting a coyote while jogging and suggested that Social Security is unconstitutional. In such a scenario, the only thing standing in the way of a President Perry is Willard Mitt Romney.

So far, Democrats and like-minded interest groups have been assuming that Obama can beat Perry more easily than Romney – and that they therefore need fear Perry less than Romney. “I was praying Perry would get in the race,” a former White House aide involved in Obama’s re-election campaign told Reuters last month.

Public opinion surveys support that attitude. A poll released on Thursday by Bloomberg News found Obama with a comfortable lead over Perry, 49-40. But his edge over Romney was 48-43. That followed a Public Policy Polling survey finding Obama with an 11-point lead over Perry but only a 4-point advantage over Romney. The key difference: Among independents, Obama trailed Romney by two percentage points but led Perry by 10.

And so Democrats have been trying to make Romney look just as out-there as Perry. Rather than go after Perry for his statements about the Ponzi scheme known as Social Security, the Democratic National Committee has been trying to make the case that Perry and Romney are indistinguishable on the topic. The DNC arranged a press conference call this week to pronounce Romney “just as dangerous” as Perry.

Similarly, the liberal group Americans United for Change put out a report arguing “Romney, Perry = Same Reckless Goals for Social Security.” Does the group really believe President Romney would be just as harmful to Social Security as President Perry? “Absolutely,” the group’s communications director, Jeremy Funk, told me.

I disagree. There may not be a whole lot of difference in their stated policies in this campaign, but Romney has a well-known history of more liberal positions on health care, climate change, gay rights and abortion. And while Romney is calculating to a fault, Perry’s bluster gives you the sense he’d resolve a trade dispute with Canada by nuking Ottawa.

Encouraging Perry’s candidacy is too dangerous a game for Democrats. Since World War II, no president with an approval rating as low as Obama’s (now hovering around 40 percent) has been reelected. And polls showing Perry to be weaker than Romney against Obama should be small comfort. In January 1980, a Harris poll found that President Jimmy Carter was polling four percentage points better against Ronald Reagan than he was against George H.W. Bush. Carter was more than 30 points ahead of both at the time, but, because of the electorate’s sour mood, wound up losing to Reagan by 10.

It’s reasonable to think the same could happen to Obama in the likely event that economic numbers don’t improve much. “What should the White House do now?” Democratic strategist James Carville asked in a commentary this week. “One word came to mind: panic.”

So, given these growing fears that Obama may lose in 2012 to any Republican with a pulse, maybe it’s time for Democrats to stop hoping that Perry will be the next Barry Goldwater. There’s admittedly not much they can do to shape the outcome of the presidential primaries, but they might wish to think twice before using their rapid-response teams to help Perry bury Romney.

One party operative close to these decisions told me there have been a “lot of conversations” about the dilemma, with some labor and environmental groups arguing for easing up on the anti-Romney message machine out of a belief that he would be the “lesser of two evils.”

Good thinking. If Obama is doomed, who would Democrats rather have in possession of the nuclear suitcase: the technocratic Romney, or the coyote-shooting Perry?

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