Montana Democrat and expected 2020 presidential candidate Steve Bullock vetoed a bill that would have ensured newborns who survive abortion receive life-saving care.

Gov. Bullock vetoed the Born Alive Infant Protection Act, which was passed by both chambers of the Republican-controlled legislature. Bullock, who did not respond to requests for comment, became the second Red State Democratic governor to block such protections after North Carolina's Roy Cooper vetoed a similar bill in April. His decision comes as he prepares to enter the 2020 Democratic primary.

Republicans introduced the legislation following Virginia Democratic governor Ralph Northam's controversial remarks in support of late-term abortion. Northam, a career doctor, said that life-saving care could be withheld from an abortion survivor unless a mother requests it.

"I can tell you exactly what would happen. The infant would be delivered. The infant would be kept comfortable. The infant would be resuscitated if that's what the mother and the family desired, and then a discussion would ensue between the physicians and the mother," Northam said.

Bullock, a two-term governor, has campaigned as a moderate Democrat, which helped him to win re-election with 50.3 percent of the vote even as President Trump won the state with 56 percent. The veto brings him firmly in line with the crowded primary field. Every Democratic presidential candidate in the U.S. Senate voted against newborn protections. Terry Schilling, executive director of the American Principles Project, said his "radical" abortion position was a "missed opportunity" for the moderate wing of the Democratic Party.

"If Democrat extremism on abortion wasn't already clear, look at supposed moderate Democrat governor Steve Bullock's veto—a bill that would simply protect babies who are born alive from being killed is a bridge to far for even the most centrist Democrat," Schilling said.

Pro-life activists pledged to make the Born Alive Act a centerpiece of the 2020 campaign. Marjorie Dannenfelser, president of the pro-life Susan B. Anthony List, said the group will focus on Bullock's "extremist record" on the issue, pointing to polling that has shown that about 80 percent of voters, including a majority of Democrats, support newborn protections. SBA List has launched a $200,000 ad campaign in North Carolina and Montana to highlight the Democrats opposition to caring for abortion survivors.

"Once again Governor Bullock sides with abortion extremists, going so far as to veto compassionate, popular legislation designed to provide care for children who survive failed abortions," Dannenfelser said in a statement. "Governor Bullock is no moderate when it comes to abortion, and we're exposing his extremist record to the voters."

Republicans do not have the votes to overturn the veto. Montana requires a two-thirds majority to push the bill through, but fell two votes short in Senate and 12 votes short in the House of reaching that threshold.