Here's the bottom line problem...
When a candidate is looking for a running-mate to be a game changer, it means he's pretty much already lost.
Some examples-
1984- Walter Mondale Breaks new ground by picking a female running mate, the first woman on a major party ticket. Until we found about her connections to mobbed up NYC politics, anyway... He goes on to lose 49 states.
1996- Bob Dole, realizing not much else is engendering enthusiasm for his campaign, picks old rival Jack Kemp to fire up the Supply Siders and social conservatives. He loses to Clinton by a bigger margin than Bush-41 did.
2008- Trying to fire up conservative enthusiasm, John McCain picks Sarah Palin, who seems like a good choice intially, until we find out she knows nothing about foreign affairs or how government actually works at the federal level. He loses by a healthy margin...
So now we have Willard trying to fire up the GOP base by picking someone they are enthusiastic about, as opposed to him... If he's having to still fire up his base less than 100 days from an election, he's probably in bad shape.
A better criteria. Someone asked Bill Clinton why he picked Al Gore, who added nothing to the ticket in terms of regional or media appeal. Clintons' response-
"I might actually die in office."
Is there a one of you that thinks that if Romney were to "Get into the Celestial Heaven", Paul Ryan at 42, with no business or managerial experience, would really be able to run the country?