The Times describes progressive angst about Hillary's VP pick:
But as Mr. Kaine sought to flex his language skills to appeal to Hispanic voters, he and Mrs. Clinton were also trying to mollify a growing backlash from the left against his record of support for global trade deals, which many voters in Rust Belt states blame for the loss of American manufacturing jobs.
Mr. Kaine was one of 13 Senate Democrats to vote in support of giving President Obama “fast track” authority on the Trans-Pacific Partnership, the 12-nation pact that has become a lightning rod this election year. In a clear sign of concern that the issue could be damaging, aides to both Democrats signaled on Saturday that Mr. Kaine would soon publicly adopt Mrs. Clinton’s current position on the deal and say that he no longer supported it in its current form.
Of course he will 'evolve' on trade. And like Hillarity!, he is also strongly in favor of comprehensive immigration reform:
Mr. Kaine supports Mr. Obama’s executive actions that would have shielded as many as five million undocumented immigrants from deportation and allowed them to legally work in the United States. He also backs a comprehensive immigration overhaul that would allow those living in the country illegally to gain legal residency if they pay taxes and a fine.
Where Mrs. Clinton stands: Mrs. Clinton has vowed to restore and expand Mr. Obama’s executive actions and to protect the parents of children who are in the country legally. She is expected to push for the comprehensive immigration overhaul in her first 100 days if she is elected president.
Well, excellent. Let's have the Democratic candidates pound the table for gun control and de facto open borders and the Republicans do the opposite, and we can see where the country comes out.
Of course the losing side will claim, with good reason, to have been represented by a flawed messenger.
More on progressive problems with Kaine at Politico.