After the election you have to govern. That is an opportunity for some and the undoing of others. Recall Virginia Gov. Tim Kaine. He won the governorship of a key swing state, was on the short list for Obama’s VP, accomplished virtually nothing as governor, presided as head of the DNC over a disastrous run of high-profile Democratic losses, and is now everyone’s favorite whipping boy. What ever happened to Tim Kaine? Well, he couldn’t do his job well. So he ends, at least for now, a promising political career.

Last year, Chris Christie and Bob McDonnell won high-profile gubernatorial races. McDonnell is sticking to his no-tax pledge and has unveiled an impressive charter-school program. He’s setting out to do precisely what he said he would, including selling off state-owned liquor stores. He seems serious about governance. If he is, he’ll avoid his predecessor’s fate.

Then there is Chris Christie. He’s also doing what he promised. He appointed a school-choice advocate to the howls of the teachers’ union. And he has announced a real spending freeze:

Announcing the freeze on $1.6 billion of unspent money, Mr. Christie was blunt: “Today, we come to terms with the fact that we cannot spend money on everything we want. Today, the days of Alice in Wonderland budgeting in Trenton end.”

That seems like a better idea than hiking taxes, if the aim here is to fix the gaping hole in the state budget. The liberal tax-and-spend policies of his predecessors have been stark and debilitating for his state:

From 2004-2008, author John Havens found “a large decline in the number of wealthy households entering New Jersey” as well as “a moderate increase in the outflow of wealthy households leaving.” The result: a net decline of $70 billion in household wealth while the “expected giving” became a net outflow of $1.132 billion.

So what happened in 2004? The study doesn’t purport to explain what caused the wealth movements. But the state’s most notable economic policy event that year was an increase in its top income tax rate to 8.97% from 6.37%, on incomes starting at $500,000. That’s a 40% increase.

Christie also seems to be in the “sober about governance” category. The lesson here for politicians of both parties is quite simple: you have to deliver. If McDonnell and Christie make good on their promises and continue their early focus on smart reform, fiscal sobriety, and conservative economic policy, they will become the models for the next generation of conservative governors and presidential hopefuls.

And, yes, that brings us back to Obama. At this point he seems headed for Tim Kaine-like flash-in-the-pan status. All that anticipation and so little ability. So much hype was followed by virtually no interest in doing the job to which he was elected. Challengers have the luxury of convincing voters to take a leap of faith; incumbents must defend what they have done. And if they don’t deliver, no amount of hype and no blame-shifting is going to rescue them. That is why, I suspect, Obama now thinks out loud about a single term. It could not have escaped his notice that he is not remotely pulling a ” B+” in the presidency.