The more I think about it, the more I think Ryan was a smart pick for Romney.
The Ryan pick is not show of strength. Romney's plan seems to have been to to stay vague, complain about Obama and the economy, and coast to victory by keeping himself and his part out of the spotlight. The Ryan pick is an acknowledgement that the plan wasn't going so well.
Ryan brings a lot to the ticket. He's the movement conservatives hero and the favorite wonk of GOP elite. This helps Mitt with a still-suspicious base. Ryan is good looking, good-natured, is not a known culture-warrior, articulate, a loyal partisan, and has a particular talent for presenting radical policies with soothing manner and a straight-face.
Paul Ryan does bring substantial baggage in the form of his sweeping, transformative budget blueprints. There's concern that his extreme positions will scare off moderates and elderly. But, until yesterday, anyone who knew how Paul Ryan was also knew how they were going to vote. The low-information middle has never heard of this guy. This gives both parties to the chance to try and define him.
The big question is will the Ryan Budget become the Romney (or the Ryan-Romney) Budget? Democrats will push for it. They would love to run a choice campaign, know a big target when the see it, are sure to mention Ryan's-plan-to-end-Medicare at every opportunity. Republicans will push for it as well. They've already voted for it twice. Ryan's policy initiatives are what catapulted him to prominence and led the GOP powers that be push for him to be on the ticket.
The person least interested in seeing the Romney-Ryan ticket run on the Ryan plan is probably Mitt Romney. Ultimately, I expect him to (semi-successfully) move away from the Ryan plan. If Romney wanted to run on the details for the Ryan plan (such as they are), Ryan would be an obvious assent. But if Romney wants to run away from the plan, then neutralizing Ryan by drawing him close, is also a smart plan. Ryan won't be an independent voice calling the shots from Congress and nobody will push the plan without him.
The Romney campaign has been maddeningly vague up until now. Every policy issue has been answered with a mish-mash of contradictory talking points and devoid of substance. The Ryan pick might mark a move toward and honest policy discussion. But since both Ryan and Romney have reputations as policy wonks there's a serious risk that they will simply try to ride their repudiations and continue to avoid policy specifics. They can wave in the general direction of their various "plans" while declining to offer anything that could actually be evaluated.
Both liberals and conservatives are clamoring for battle over their policies and visions for the country. The Ryan pick offers the promise of a campaign with renewed focus on policy and legislative proposals. We should all hope, and strive to insure, the rest of the campaign lives up to that promise.