Portman wouldn’t be a disaster. He is serious and sober. That’s good news for Romney, whose first qualification for his second in command is that he do no harm.

But a do-no-harm candidate doesn’t also have to be a do-no-good candidate. Sure, I hear the concerns that Romney might be overshadowed by a Chris Christie or a Marco Rubio. And picking a big personality or a minority-group member just as a gimmick might show insecurity.

Still, as the convention nears, Romney needs to show that he can be bold, confident and, yes, exciting.