Probably not too many.
I see a lot of people talking about how not too many people switch from Clinton to Trump because of Kaine. Obviously--this is not ground-breaking analysis. I think the idea of Kaine was to take suburban votes (the people privileged enough to care about civility and stability over actual issues) and be a little more appealing to Catholics (I guess buying into the idea she was going to bleed Catholics because of that email Fox was whining about or whatever. I guess it's just the conventional wisdom that you have to have one Catholic on your ticket nowadays. I don't think regular people have cared about if the VP is Catholic or not in a while, but no one asked me.)
The thing is, millions upon millions of Americans could've voted but didn't. A lot of them probably weren't going to no matter what, but there were probably several million who were D vs. nothing/third party or R vs. nothing/third party. Probably for weird reasons, and probably Kaine didn't matter too much. But people make a severe error to assume all voters are solid D, solid R, or
Pragmatic
Centrists:).
Again, Kaine didn't matter too much--and that's the issue with Kaine. It wasn't that people were like "ew, Kaine."
I'd wager a guess just about anyone who hates Tim Kaine hates Hillary Clinton more. The problem is that basically everyone who's a big Tim Kaine fan was already going to vote for Hillary Clinton no matter what. A good VP pick adds to the coalition. (An example is Pence for Trump--a lot of people felt way more safe about Trump with Pence--negating his "New York Values" i.e. making sure he's bigoted enough-- and people who Trump brought in weren't as put off as if he picked, say, Rubio.) A bad VP takes away from the coalition--frankly I think this would've happened with Hillary/Bernie. The fraction of voters who defected from Clinton because Sanders lost would've mostly just been like "wow, Bernie's another shill
" and the neoliberal suburbanites would've been worried Clinton was wavering on her steadfast positions of bombing the scary countries and ignoring wealth inequality. Warren or Brown would've been a more coherent pick.