The Clinton campaign announced Friday that Sen. Tim Kaine (D-VA) has been selected to join Hillary Clinton’s ticket as her vice presidential candidate.

“I’m thrilled to announce my running mate, @TimKaine, a man who’s devoted his life to fighting for others,” said Clinton in a tweet.

“.@TimKaine is a relentless optimist who believes no problem is unsolvable if you put in the work to solve it,” she added.

The prospect of Kaine’s selection has been criticized by some progressives due to his stances on issues including abortion as well as bank and trade regulation.

Kaine signed two letters this week calling for the regulations on banks to be eased, according to a Wednesday report published by the Huffington Post, thereby ”setting himself up as a figure willing to do battle with the progressive wing of the party.”

Charles Chamberlain, executive director of the progressive political action committee Democracy for America, told the New York Times that Kaine’s selection “could be disastrous for our efforts to defeat Donald Trump in the fall” given the senator’s apparent support of the Trans-Pacific Partnership (TPP). Just before Clinton’s campaign made the official announcement that Kaine had been selected, the senator praised the TPP during an interview with the Intercept, though he signaled he had ultimately not decided how he would vote on the matter.

Kaine’s record on reproductive rights has also generated controversy as news began to circulate that he was being considered to join Clinton’s ticket. Though Kaine recently argued in favor of providing Planned Parenthood with access to funding to fight the Zika virus and signed on as a co-sponsor of the Women’s Health Protection Act—which would prohibit states and the federal government from enacting restrictions on abortion that aren’t applied to comparable medical services—he has also been vocal about his personal opposition to abortion.

In a June interview on NBC’s Meet the Press, Kaine told host Chuck Todd he was “personally” opposed to abortion. He went on, however, to affirm that he still believed “not just as a matter of politics, but even as a matter of morality, that matters about reproduction and intimacy and relationships and contraception are in the personal realm. They’re moral decisions for individuals to make for themselves. And the last thing we need is government intruding into those personal decisions.”

As Rewire has previously reported, though Kaine may have a 100 percent rating for his time in the Senate from Planned Parenthood Action Fund, the campaign website for his 2005 run for governor of Virginia promised he would “work in good faith to reduce abortions” by enforcing Virginia’s “restrictions on abortion and passing an enforceable ban on partial birth abortion that protects the life and health of the mother.”

As governor, Kaine did support some existing restrictions on abortion, including Virginia’s parental consent law and a so-called informed consent law. He also signed a 2009 measure that created “Choose Life” license plates in the state, and gave a percentage of the proceeds to a crisis pregnancy network.

Regardless of Clinton’s vice president pick, the “center of gravity in the Democratic Party has shifted in a bold, populist, progressive direction,” said Stephanie Taylor, co-founder of the Progressive Change Campaign Committee, in an emailed statement. “It’s now more important than ever that Hillary Clinton run an aggressive campaign on core economic ideas like expanding Social Security, debt-free college, Wall Street reform, and yes, stopping the TPP. It’s the best way to unite the Democratic Party, and stop Republicans from winning over swing voters on bread-and-butter issues.”

CORRECTION: A previous version of this article included a typo that misidentified Sen. Tim Kaine as a Republican. We regret this error.