Standard operating procedure in presidential campaigns holds that running mates should campaign separately. The rationale is obvious; it allows the campaign to be in two places at once. Twice as many fundraisers, events, meeting with party leaders, etc.
The only campaign I know of that broke this protocol was Clinton-Gore in 1992. The plan had been to have the candidates go their separate ways after a flurry of joint appearances following the selection of Al Gore. But the dynamic between the two was so strong and electrifying that, over the often bitter objection of staff, the two men decided to campaign together on a regular basis.
I was thinking about all this as I followed the aftermath of the Paul Ryan announcement. These two men also seem to have a strong chemistry, upping each other's game. Ryan is particularly good at explaining Romney in a way that helps overcome many months of awkwardness and Ryan has much better rap about how Obama is imperiling our future.
But after a weekend of joint appearances the two candidates are going their separate ways. I think that is a lost opportunity. Romney needs Paul Ryan at his side right now. It is a case of one plus one equals three. (Kind of like Paul Ryan's budget — sorry, couldn't help it.)