Democrats promised to throw every obstacle in the way of President Donald Trump's pick to replace Justice Anthony Kennedy on the Supreme Court, but Senate procedures and election-year politics don't give them much of a chance.

Republicans last year eliminated the 60-vote barrier to setting a vote for Supreme Court nominees, leaving Democrats without the tool of a filibuster. Their best hope would be to hold Senate Democrats united in opposition and peel off at least two Republicans to vote against Trump's nominee.

With several Democratic senators facing re-election in November in states won overwhelmingly by Trump and GOP lawmakers showing little appetite for crossing a president with a tight grip on GOP voters, that hope is dim — and may rest squarely on the two female Senate Republicans, Susan Collins and Lisa Murkowski.

Less than an hour after Kennedy announced his retirement on Wednesday, Senate Majority Leader Mitch McConnell said the chamber would move swiftly once Trump nominates a replacement with a confirmation vote in the "fall," throwing the issue directly into the middle of the midterm elections.

Senate Minority Leader Chuck Schumer countered by calling on Republicans to delay a confirmation until after the elections, saying voters have the right to weigh in on "the most important Supreme Court vacancy for this country in at least a ­generation."

A Supreme Court fight right before already heated November elections will energize voters in both parties, with divisive issues including abortion rights and access to health care hanging in the balance. It will serve as yet another reminder of the high stakes in deciding which party controls the House and Senate and may bolster turnout in ways no one can yet predict.

Demonstrators opposed to abortion outside the U.S. Supreme Court building in Washington, June 26, 2018. A state law requiring “crisis pregnancy centers” to supply women with information about abortion likely violates the First Amendment, the Supreme Court ruled on Tuesday in blocking the law. The case, National Institute of Family and Life Advocates v. Becerra, concerned a California law that requires centers operated by opponents of abortion to provide women with information about the availability of the procedure. (Erin Schaff/The New York Times)

"It's an election season. It's obviously a politically charged issue as these fights always are," said Sen. John Thune of South Dakota, the No. 3 GOP leader. "For our base, for their base, too, it kind of galvanizes them and makes them very motivated and engaged. I suspect that happens on both sides."

Some Dems in tight spot

One thing is clear, though: the half-dozen incumbent Democrats in competitive races in states Trump won in 2016 — including Joe Donnelly of Indiana, Joe Manchin of West Virginia and Heidi Heitkamp of North Dakota — are in a tight spot. Those three senators voted for Trump's first Supreme Court nominee, Neil Gorsuch.

This time they will be under more intense pressure to stick with Democrats on the confirmation, even as they're campaigning in states where many voters are likely to favor Trump's nominee. Republicans have credited the vacancy on the court left by the death of Justice Antonin Scalia with helping to galvanize their voters behind Trump in 2016 after they blocked then-President Barack Obama's nomination of Merrick Garland.

"There are no good choices for them here," said Jennifer Duffy, Senate editor of the nonpartisan Cook Political Report.

Manchin treaded carefully Wednesday, declining to back the calls by Schumer and many other senior Democrats for a delay. "Senators have a responsibility to do our jobs as elected officials and this includes our constitutional obligation to advise and consent on a nominee to fill this Supreme Court vacancy," he said in a statement.

Kennedy's position in the court's center guarantees a fierce confirmation fight. Trump vowed during the campaign to appoint justices who would vote to overturn Roe vs. Wade, the 1973 decision that legalized abortion, and his appointment to replace Kennedy could make that a reality.

Kennedy voted last week with a 5-4 conservative majority to uphold Trump's travel ban as a legitimate move to protect national security, rejecting arguments that the president singled out Muslims. It was the most prominent in a series of narrowly decided cases this term that will have interest groups on both sides devoting massive resources to sway senators.

Kennedy's departure puts the Supreme Court at a tipping point. Another Gorsuch-type nominee could create the most conservative court since the justices blocked a number of President Franklin D. Roosevelt's New Deal programs in the 1930s.