President Obama on Tuesday at The Associated Press luncheon during the ASNE Convention in Washington. (Pablo Martinez Monsivais/AP)

But polls can have multiple interpretations. For example, President Obama’s job approval/disapproval numbers seem to be trending in his direction. So maybe it means that voters in general are moving his way?

Maybe. Or maybe not.

A poll last month by CNN/ORC International asked whether people approved or disapproved of Obama’s handling of his job. It showed Obama had pushed his approval rating up to 51 percent. Some 45 percent disapproved.

That’s a huge shift from his numbers back in August, when the same pollsters found that only 44 percent approved and 54 percent disapproved.

Because of the improving economy or the GOP primaries? Possibly.

But the pollsters asked a follow-up question:

“1a. (IF DISAPPROVE) Do you disapprove because you think his policies and actions since he became president have been too liberal, or because you think his policies and actions have not been liberal enough?”

Those who disapproved because he was too liberal (35 percent) were virtually the same in August (36 percent) and March (35 percent.)

What changed was the number who disapproved because they thought he was not liberal enough (the single-payer advocates and assorted liberals).

That number dropped dramatically from 16 percent in August to 8 percent in March, accounting for virtually all of Obama’s improved numbers.

So maybe some of what’s happening is that liberal Democrats are drifting back to the Democratic base?

In which case, Romney can forget the Etch-a-Sketch and just call Ralph Nader or someone to siphon off the libs.