We wrote this morning that Senate Majority Harry Reid has picked a fight with former Massachusetts governor Mitt Romney on the latter’s tax returns that the Nevada Democrat will almost certainly win.

Just to put a finer point on that, well, point, we went looking for the latest favorable and unfavorable ratings for both men. Then we put them into two pie charts.

Here’s Reid’s — from a January Pew poll:

And here’s Romney’s from a July Pew poll:

Notice the difference? Neither man is popular with the public — their unfavorable ratings are higher than their favorable ratings — but Romney is FAR better known nationally than Reid.

Just 16 percent of people in the July Pew poll said they didn’t have an opinion about Romney or didn’t know enough about him to form an opinion. Forty four percent — almost three times as many — didn’t know who Reid was or didn’t have an opinion about him.

And that is the essence of Romney’s problem when it comes to Reid. A near-majority of the public simply don’t know who Reid is and, therefore, trying to turn him into a figure of derision almost certainly won’t work.

That realization is likely why the Romney campaign has begun to pivot from attacking Reid into suggesting that it’s the Obama campaign that is, in fact, behind this attempt to force the Republican presidential nominee into releasing his tax returns.

The question now is whether that pivot will work.