Democratic opposition to President Donald Trump's U.S. Supreme Court nominee grew on Monday while the White House demanded a "fair, up-or-down vote" in the Senate on confirming Neil Gorsuch to the lifetime post.
Four more Democratic senators added their support to a growing effort to block a confirmation vote through the use of a procedural hurdle called a filibuster that requires 60 votes in the 100-seat Senate to allow a confirmation vote requiring a simple majority. Republicans control the Senate 52-48.
There are now 20, up from 16 on Friday, who have backed Democratic leader Chuck Schumer's filibuster call.
Democratic opposition to Gorsuch could prompt a Senate showdown over the confirmation of the conservative appeals court judge from Colorado, but Republicans could change the Senate's rules to disallow filibusters against Supreme Court nominees.
Trump is seeking to avoid another setback in Congress after major healthcare legislation he supported was pulled from the House of Representatives floor amid opposition within his own party on Friday.
The confirmation of Gorsuch, 49, would restore the nine-seat court's conservative majority, a major campaign promise for Trump.
The latest Democrats to join the fight include Bill Nelson of Florida, who expressed "real concerns" Gorsuch would be hostile to voting rights, sympathetic to efforts to lift campaign finance restrictions and support businesses over workers and consumers.
The other three Democrats to have newly announced their opposition were Judiciary Committee members Mazie Hirono of Hawaii and Al Franken of Minnesota, as well as Jack Reed of Rhode Island.
Democrat Patrick Leahy of Vermont, a member of the Judiciary Committee that held confirmation hearings last week, said he generally opposes filibusters but added that Gorsuch would face such a move if he does not adequately answer written questions.
"An attempted filibuster of a Supreme Court nominee is rare, and to do so in this context, with such an eminently qualified and brilliant judge, is nothing short of obstructionism," White House spokesman Sean Spicer said, noting Leahy's comments against taking part in a filibuster.
"He deserves a fair, up-or-down vote," Spicer added.
The committee is due to vote next Monday on sending the nomination to the full Senate.
Nelson is one of 10 Democrats who conservative activists had hoped would join Republicans in preventing any attempt to block a Gorsuch vote. They are all up for re-election in 2018 in states Trump won in the 2016 presidential election.
Of those, four have now said they would support a filibuster. Aside from Nelson, the others were Ohio's Sherrod Brown, Pennsylvania's Bob Casey and Wisconsin's Tammy Baldwin.
(Reporting by Lawrence Hurley; Editing by Will Dunham)