WASHINGTON- Headed toward a partisan showdown over Senate rules, Republicans and Democrats are set to open a floor debate on whether to confirm President Donald Trump's pick for the Supreme Court.

Democrats secured the necessary support Monday to block Judge Neil Gorsuch from a high court seat, leaving Senate Republican leader Mitch McConnell short of the 60 votes he needs. But the victory will only be fleeting, as McConnell is ready to lead the GOP in a unilateral floor procedure change so significant that it's been dubbed the "nuclear option." It lowers the confirmation threshold to a simple majority in the 100-member Senate.

The fight was assured as the Judiciary Committee voted 11-9, along party lines, to send Gorsuch's nomination to the Senate. McConnell has vowed Gorsuch will be confirmed Friday.