Brett Kavanaugh needs 51 votes to become the Supreme Court's next associate justice, and his future rests in the hands of just a handful of senators.
A few moderate Republicans and moderate Democrats, some of whom face contentious reelection races this fall, are as of yet undecided on whether to support Kavanaugh. Some of the undecided Democrats already supported Justice Neil Gorsuch in his confirmation process last year, making it potentially easier for them to vote for Kavanaugh.
In the days and weeks ahead, these are the senators to watch, as they meet with Kavanaugh, review his past opinions and pepper him with questions to determine what kind of justice he might be.
Sen. Lisa Murkowski, a moderate Republican from Alaska, has said she will take time to review Kavanaugh's record, giving no indication where she might land Monday night.
"I intend to review Judge Kavanaugh's decisions on the bench and writings off the bench, and pay careful attention to his responses to questions posed by my colleagues on the Senate Judiciary Committee," Murkowski said in a statement after the announcement.
Murkowski is one of two key female GOP senators who will play a key role in Kavanaugh's path to confirmation.
The other key female GOP senator in Kavanaugh's confirmation process is Maine's GOP Sen. Susan Collins, who has said she wouldn't want a justice who would move to overturn Roe v. Wade. From among Mr. Trump's top contenders leading up to Monday night, Kavanaugh is perhaps most likely to secure Collins' support.
Kavanaugh has not weighed in heavily on the matter of abortion rights, although Senate Minority Leader Chuck Schumer, D-New York, has pledged to bring up the topic. How Kavanaugh responds could be a significant determining factor for Collins.
On Tuesday, Collins was swarmed by reporters on Capitol Hill, trying to glean any insight on how she might vote. She said little.
Kentucky's Sen. Rand Paul —when he thinks the federal government is spending too much or invading personal privacy — has concerns that differ from his GOP Senate colleagues. Paul, opposed to "big brother"-like big government, is likely to raise questions about Kavanaugh's decisions on Fourth Amendment-related cases. Kavanaugh, for instance, supported the highly controversial federal metadata collection program, declaring in 2015 that "the government's metadata collection program is entirely consistent with the Fourth Amendment."
Paul tweeted that he will look into Kavanaugh's record "with an open mind."
Paul's potential concerns may not be to worrisome for Republicans, however — Paul has been known to voice opposition, even in the form of a filibuster, before voting with his GOP colleagues.
Heitkamp, a Democrat in a state that voted for Mr. Trump, issued a lengthy statement Monday night saying she takes her role to vet Supreme Court nominees "incredibly seriously," and will conduct a thorough review of Kavanaugh's record. Heitkamp is up for reelection in November in a race that is considered a toss-up.
She was one of three Democrats toin his Supreme Court confirmation process last year, increasing the likelihood that she will also go for Kavanaugh.
"An exhaustive and fair process took place for Justice Gorsuch, who I supported, and it should and must take place again now," she said in a statement Monday night. "And that's the kind of leadership North Dakotans expect from their senators."
West Virginia's Manchin, a vulnerable Democrat who is up for reelection in the state that voted for Mr. Trump over Hillary Clinton by the greatest margin, has much at stake. Mr. Trump and Manchin's Republican opponent, Patrick Morrisey, have already been slamming Manchin for times he's sided with Democrats, such as on last year's tax overhaul vote. If Manchin votes against Kavanaugh, it will be more ammunition in the GOP arsenal come November.
Manchin was was also among the three Democrats.
Manchin says he'll review Kavanaugh's record closely — and with particular attention to health care. That's because, he says, the Supreme Court will ultimately determine whether health insurers will be prohibited from denying insurance to hundreds of thousands of his constituents with pre-existing conditions.
"The Supreme Court will ultimately decide if nearly 800,000 West Virginians with pre-existing conditions will lose their healthcare. This decision will directly impact almost 40 percent of my state, so I'm very interested in his position on protecting West Virginians with pre-existing conditions. As I have always said, I believe the Senate should hold committee hearings; senators should meet with him, we should debate his qualifications on the Senate floor and cast whatever vote we believe he deserves. I look forward to meeting with Judge Kavanaugh, examining his rulings and making a determination of whether to provide my consent."
Asked Tuesday if that means he wants assurance from Kavanaugh on the issue in order to vote for him, Manchin said he wants to do a deep dive looking at his rulings and findings.
Alabama's Jones, another, won his seat last year by defeating Roy Moore, the Trump-supported Republican Senate candidate accused of engaging in inappropriate relationships with underage girls in his 30s. Jones has a large GOP base to keep content, if he hopes to remain in the Senate in the future. That's something he has to keep in mind on significant votes such as confirming Kavanaugh.
At the moment, Jones is undecided, saying he'll wait to conduct an "independent review" of Kavanaugh's record.
"Tonight's announcement is only a first step. A thorough vetting of Judge Kavanaugh's body of work will be critical for the Senate to fulfill its shared responsibility—which I take very seriously," Jones tweeted Monday night. "I will be diligent in measuring the record and in undertaking an independent review."
Like Manchin, Indiana's Donnelly is a vulnerable Democrat heading into the 2018 midterms. Mr. Trump has already campaigned against him in Indiana, slamming "sleeping Joe" as someone who always sides with the Democrats. In a state that Mr. Trump won in 2016, Donnelly has to show he can work with Republicans.
Donnelly has yet to decide how he will land on Kavanaugh. But he did vote to confirm Gorsuch last year.
"As I have said, party of my job as senator includes thoroughly considering judicial nominations, including to the Supreme Court," Donnelly said in a statement Monday night. "I will take the same approach as I have previously for a Supreme Court vacancy. Following the president's announcement, I will carefully review and consider the record and qualifications of Judge Brett Kavanaugh."