Q: Can Democrats block President Donald Trump's nominee through a filibuster?

A: No. Democrats eliminated the 60-vote threshold for most judicial nominees in 2013, frustrated by Republicans' use of the filibuster to slow and impede President Barack Obama's agenda. In turn, angered by resistance to the nomination of Justice Neil Gorsuch in 2017, Republicans abolished the limitation on Supreme Court nominees, further whittling down the scope of the filibuster.

As a result, Senate Majority Leader Mitch McConnell could bring the nomination to the Senate floor and approve it with a simple majority vote.

Q: Does McConnell have the votes to confirm a nominee?

A: It depends. Because Republican hold a slim majority — 53-47 — Democrats would need only four Republicans to join them in opposition to sink the nominee. (In the case of a tie, Vice President Mike Pence, in his role as president of the Senate, would cast a tiebreaking vote.)

Although McConnell vowed that the Senate would vote on Trump's chosen nominee, he notably made no mention of when that would occur — a signal that he was weighing the political calculus for the handful of vulnerable Republican senators facing tough races.

Given McConnell's decision to refuse so much as a hearing for Merrick Garland, Obama's pick upon the death of Justice Antonin Scalia in 2016, a handful of Republicans have signaled a desire to wait until after Election Day to approve a nomination.

Q: Who might defect?

A: Sen. Susan Collins of Maine, one of the most vulnerable Republicans facing voters this year, said Saturday that "in fairness to the American people," the Senate should not vote until after the election and that the nomination "should be made by the president who is elected on November 3rd."

Sen. Lisa Murkowski of Alaska told a local radio station in an interview before Ginsburg's death was announced that she would not vote to confirm a Supreme Court nominee before Election Day.

Other top Republicans, including Sen. Lindsey Graham of South Carolina and Chuck Grassley of Iowa, have previously expressed similar reservations given their party's blockade of Garland in 2016.

But on Saturday, Graham, a loyal ally of Trump's who is facing a more difficult than expected re-election fight, signaled that he has changed his mind since then, pointing to comments he made this year in which he said that after the bruising battle over Justice Brett Kavanaugh's confirmation, "the rules have changed, as far as I'm concerned."