• The Senate is fairly split ahead of President Donald Trump’s announcement of who he intends to nominate for the vacancy on the Supreme Court.
  • A couple of Republicans could rebuke the president and tank the potential nominee.
  • At the same time, a handful of politically vulnerable Democrats could tilt the odds in the White House’s favor.

WASHINGTON – President Donald Trump is slated to announce his nominee to fill the vacancy left on the Supreme Court by retiring Justice Anthony Kennedy on Monday, amid a polarized Senate full of partisan lawmakers who are at each others’ throats.

The Senate is tasked with vetting and ultimately confirming or rejecting whomever Trump chooses to fill the vacancy on America’s highest court. Because the Senate is split with 51 Republicans, 47 Democrats, and two independents who are members of the Democratic caucus, the stakes could not be higher for the lucky legal mind Trump nominates.

An added factor is the swiftly approaching 2018 midterm elections, in which several Democrats are facing tough re-election battles in traditionally conservative-leaning states.

The way just a handful of Republicans and Democrats in the Senate decide to vote could tip the balance of any potential nominee.

The Republicans who might say no

GOP Sen. Susan Collins of Maine has often been a thorn in Trump's side. She was unafraid to break with GOP orthodoxy on issues like health care, leading to the possibility she does the same on a Supreme Court nominee she might deem too textualist or conservative.

Collins, one of the few Republicans who supports access to abortion, said that the nominee's record and history with the subject will be a major component of whether or not she supports them.

"I would not support a nominee who demonstrated hostility to Roe v. Wade because that would mean to me that their judicial philosophy did not include a respect for established decisions, established law," Collins told CNN.

Collins made that clear when she met with Trump shortly after Kennedy's retirement at the end of June. Collins also urged Trump to "broaden his list" of potential candidates, referring to the 25 potential picks he unveiled during his presidential campaign.

Sen. Lisa Murkowski of Alaska is another Republican who sometimes rejects strict Republican orders. Like Collins, Murkowski supported Trump's first Supreme Court nominee last year in Neil Gorsuch. But the second time around, Murkowski could prove to be more difficult for the White House to get a solid yes.

At a news conference in Anchorage, Alaska, Murkowski said she hopes that Trump would nominate a justice who is philosophically similar to Kennedy, signaling a tough road ahead for the White House team.

The Democrats who might say yes

The 2018 midterm election map has created a unique situation for Trump, who will look to use political pressure on red state Democrats on the fence about his nominee.

Three Democratic senators voted for Gorsuch last year: Joe Donnelly of Indiana, Heidi Heitkamp of North Dakota, and Joe Manchin of West Virginia. A common thread with all three is that their states are very much aligned with the Trump administration on policy.

Trump has already pummeled the three senators for voting against the Republican tax cut bill during campaign rallies for their respective challengers. A vote against one of Trump's Supreme Court nominees could add a lot more fuel to the fire.

Donnelly is easily one of the most conservative or moderate Democrats in the Senate. He votes with the GOP more often than most of his colleagues and has made a point of not crossing the president.

Donnelly met with Trump the day after Kennedy's retirement, after which he remained open to supporting the future nominee.

"When the president presents the Senate with his choice for the Supreme Court, I will thoroughly review the record and qualifications of that nominee," Donnelly said in a readout of the meeting.

Heitkamp is another wildcard on the Democratic side of the aisle. Like Donnelly, she also met with Trump after Kennedy's retirement, where they discussed the court vacancy, which was right after Trump railed against her during a rally in North Dakota with her challenger, Rep. Kevin Cramer.

"Political speeches are just that, but the next day, I'm ready to get to work. As I said, if the president wants to meet with me, I'm ready to participate and advocate for North Dakota. And that's exactly what happened today," she said. "President Trump and I had a solid discussion about the Supreme Court vacancy."

And finally, Manchin is a key vote on the Democratic side that Republicans will be eager to court for Trump's nominee. Manchin said in a statement he would meet with and evaluate Trump's nominee, adding that he is open to backing the right selection.

Trump won Manchin's home state of West Virginia by more than 42 points in 2016, putting the longtime moderate Democrat on thin ice going into this November. If the pressure is enough, Manchin could likely bend to the White House's will on a Supreme Court nominee.

And all that has to happen is Republicans need at least 50 "yes" votes. In the event the Senate is split down the middle, Vice President Mike Pence can serve as the tie-breaker. Whether or not it will be that close will be up to the Republicans and Democrats previously mentioned.