WASHINGTON — Senate Democrats vowed Thursday to impede Judge Neil Gorsuch’s path to the Supreme Court, setting up a political showdown with implications for future openings on the high court.

Still irate that Republicans blocked President Barack Obama’s nominee, Democrats consider Gorsuch a threat to a wide range of civil rights and think he was too evasive during 20 hours of questioning. Whatever the objections, Republicans who control the Senate are expected to ensure that President Donald Trump’s pick reaches the bench, perhaps before the middle of April.

The Democratic leader in the Senate, Chuck Schumer of New York, was among five senators to declare their opposition to Gorsuch Thursday, even before the Judiciary Committee hearing on the nomination had ended.

Schumer said he would lead a filibuster against Gorsuch, criticizing him as a judge who “almost instinctively favors the powerful over the weak.” Schumer said the 49-year-old Coloradan would not serve as a check on Trump or be a mainstream justice.

“I have concluded that I cannot support Neil Gorsuch’s nomination,” Schumer said on the Senate floor. “My vote will be no and I urge my colleagues to do the same.”

White House press secretary Sean Spicer called on Schumer to call off the filibuster, saying “it represents the type of partisanship that Americans have grown tired of.”

A Supreme Court seat has been open for more than 13 months, since the death of Justice Antonin Scalia. Like Scalia, Gorsuch has a mainly conservative record as a federal appellate judge.

Shortly before Schumer’s announcement, Pennsylvania Sen. Bob Casey, who faces re-election next year in a state Trump won, also announced his opposition. Casey said he had “serious concerns about Judge Gorsuch’s rigid and restrictive judicial philosophy, manifest in a number of opinions he has written on the 10th Circuit.”

Democratic Sens. Tom Carper of Delaware and Ron Wyden of Oregon, and Sen. Bernie Sanders, the Vermont independent, also said they would vote against Trump’s nominee, among at least 11 senators who say they will oppose Gorsuch in the face of pressure from liberals to resist all things Trump, including his nominees.

No Democrat has yet pledged to support Gorsuch, but Sen. Joe Manchin of West Virginia has said he is open to voting for him. Manchin spoke Wednesday after watching the nominee emerge unscathed from testimony to the Judiciary Committee.

Senate Majority Leader Mitch McConnell, R-Ky., said Democratic threats of delay, in the face of what he called Gorsuch’s outstanding performance, stem from their base’s refusal “to accept the outcome of the election.”

In an interview with The Associated Press on Tuesday, Senate Majority Leader Mitch McConnell seemed ready to change Senate rules, if necessary, to confirm Gorsuch with a simple majority rather than the 60 votes now required to move forward.

Such a change also would apply to future Supreme Court nominees and would be especially important in the event that Trump gets to fill another opening and replace a liberal justice or Justice Anthony Kennedy, the court’s so-called swing vote. In 2013, Democrats changed the rules to prohibit delaying tactics for all nominees other than for the high court.