Carter’s critique of former Massachusetts Gov. Mitt Romney is generous. I hope the Republican nominee, regardless of who it is, will be able to thread the needle between Republican critics and the Democratic attack machine.

Romney is a well-established figure; a large portion of the Republican electorate has a clear picture of him. So far, that impression has kept him near or at the top of the field. By any measure, he is in good shape. At the least, he certainly would not trade places with any of his rivals.

But he has to deal with a low-grade fever in my party.

We think the country is in too much trouble and the presidency is too vital to America’s future for us to elect a leader who doesn’t possess clear thinking on core economic issues and reliably conservative instincts on everything else. The questions about Romney’s sincerity and authenticity give some Republicans pause. This problem will be managed, not solved. It is the negative stereotype his GOP critics want to enhance, provoke and exploit, and it is among the attacks he would face in a general election.

A problem that torments the Obama forces every day is the need for the Republican nominee to be a good bad guy for President Obama to run against. They want someone that they can demonize, someone who makes their rants appear credible. Simply put, Romney is not a good bad guy. He just doesn’t seem evil, mean-spirited, stupid or eager to throw the less fortunate out in the snow. And, on a stage with Obama, it will be easy to tell who the happy, good-natured one is.

Remember Minnesota Gov. Tim Pawlenty? His whole campaign was built on the premise that he would not be a good foil for Obama. That if he were the GOP nominee, he would be sufficiently bland, almost anonymous, so that Obama would have to run against himself and Pawlenty would blend into the background, only to emerge on a platform in front of the U.S. Capitol for his swearing in. Obviously, it didn’t work and Pawlenty is out of the race, but there was some wisdom to his analysis, and much of it still applies. Perhaps Pawlenty got out too quickly.

Our eventual nominee needs to be credible, at peace with the Tea Party, unalarming and unusually quiet.

This election should rightfully be about Obama. Period.