Sen. Bernie Sanders (I-VT) has launched an aggressive campaign to defeat Brett Kavanaugh's nomination to the Supreme Court. It's taken him from the cable airwaves to a trio of Midwestern states so far. But as he ramps up the effort, the Senator has kept an eye back on D.C. where, he worries, Democrats may not be able to unify the ranks against Trump’s pick.

“Of course,” Sanders told The Daily Beast in an interview last week when asked if he worries about red-state Democrats voting in favor of the nominee as they face daunting electoral prospects in November. “My hope is that the Democrats will stay united and that we will successfully get a couple of Republicans to join us. But obviously, if we’re going to win, Democrats have got to stay united on this issue. But we start off this fight against a very united Republican party, a party that is very fearful of the president. But we have got to do everything we can to pry loose a couple of Republican senators.”

Sanders’ fears aren’t unfounded. When President Trump nominated Supreme Court Justice Neil Gorsuch, towards the beginning of his first term in office, Sens. Heidi Heitkamp (D-ND), Joe Manchin (D-WV) and Joe Donnelly (D-IN)—all of whom are in tough re-election contests this cycle—voted to confirm him.

So far, those three senators have remained guarded as to how they will vote on the Kavanaugh nomination. But the pressure for them to vote for confirmation is not insignificant. The Judicial Crisis Network, a conservative legal group, has reportedly bought an additional $1.4 million in ads, now $3.8 million total, targeting those three senators specifically in addition to Sen. Doug Jones (D-AL).

Should all Senate Republicans vote for confirmation, the pressure on conservative Democrats to follow suit will be even stronger. Under such a scenario, Kavanaugh’s bid would already have enough support for passage. A no vote would show ceremonial opposition but would also give Republicans a bit of campaign fodder during the close of the midterm elections.

For that reason, Sanders said that the main onus of a campaign to defeat Kavanaugh had to be placed on self-declared pro-choice Republicans first.

“It’s not acceptable, it seems to me, for a senator to say ‘Well, I am pro-choice’ or ‘I am supportive of the Affordable Care Act’ and then very knowingly allow somebody to succeed on the Supreme Court who will undermine those beliefs and basically end legislation which provides those protections,” the independent senator said, referring to Sens. Susan Collins (R-ME) and Lisa Murkowski (R-AK).

Sanders spoke to The Daily Beast before heading off to a series of rallies in Minnesota, Wisconsin and Pennsylvania, meant to serve as rallying cries against Kavanaugh as well as boosts for a slate of progressive candidates. The Senator said he had not, so far, gotten any indication from red-state Democrats in the caucus about what they’re thinking on the nomination. But he emphasized that the fight is not going to take place inside the beltway, rather with natural energy on the ground akin to red-state actions like the West Virginia and Oklahoma teachers’ strike.

“I think it is important for us to remind the American people that if you are concerned for example about a woman’s right to control her own body that we have a president who made it very very clear that he will only appoint people who overturn Roe v. Wade,” Sanders told The Daily Beast. “The point is to bring Supreme Court decisions down to Earth. And make it clear this is not some kind of academic, intellectual exercise that nine people are engaged in. These are life and death issues. And this president has made it very clear about what side he is on and who he wants on the Supreme Court.”