No change. I guess he might help among the hardcore social conservative voters who were for Cruz before the primary process even started, but I have to imagine all the persuadables have gone to Trump already. Might actually marginally hurt in Indiana, but I doubt Trump's losing there outside of a total collapse scenario anyway.
Donald Trump is such a unique figure, and people are so set and decided in their opinions of him, that it's hard to imagine any VP choice really meaningfully helping or hurting.
What about the near 20% undecideds regularly showing in polls?
Most of these are people who have strongly unfavorable opinions of Trump and Hillary. I don't think Pence will help Trump with this group too much; he's not enough of a unique, narrative-changing figure. I see a large number of these people ultimately not voting, another large fraction voting third-party, and then whichever of Hillary or Donald gets a larger number only gains a margin of 1-2%. There will not be a mad rush towards one of the candidates unless the favorables of one of the candidates improve, and that doesn't happen in a negative campaign (which Hillary and Donald both seem intent on waging). So I think in the end that'll be much less relevant than you think.
Poll
