Scott Rasmussen

Still, the way Portman is introduced to the public will matter more than his resume. Half the nation's likely voters (47 percent) have absolutely no opinion one way or the other on Portman. They don't know who he is. Another 43 percent have only soft opinions. They're not sure they know who he is. Just 11 percent currently have strong views one way or the other.

That means, if Portman is selected, nine out of 10 Americans will have their opinions shaped after the nominee is picked. Portman, by the way, is the rule, not the exception. Some other prospective nominees are even less well known than he is.

So enjoy the summer guessing games for now. But discount most of the political analysis until you see how Romney's choice survives his or her introduction to the nation.

Scott Rasmussen

Scott Rasmussen is founder and president of the Rasmussen Media Group. He is a political analyst, author, public speaker and columnist for Creators Syndicate.