(CNN) -- The Senate Judiciary Committee is holding another round of hearings Thursday on Supreme Court nominee Neil Gorsuch, this time with 28 outside witnesses who will testify both for and against him, as two Democrats announced they're voting no on his nomination.
Senate Minority Leader Chuck Schumer and Sen. Bob Casey both said Thursday they'd vote no on Gorsuch's nomination. Casey had been one of a dozen Democratic targets Republicans had hoped to woo as Gorsuch will need at least 60 votes to be confirmed and there are only 52 GOP members in the chamber.
Schumer of New York, a vocal critic of President Donald Trump's nominee to the high court, also made clear that Gorsuch will face a filibuster from Democrats, meaning the judge will need at least eight Democratic votes to advance to a final vote on confirmation.
No Democrats have come out in favor of him yet.
Schumer's announcement came minutes after Casey, a Pennsylvania Democrat running for re-election in a state Trump won, told reporters he, too, would vote against Gorsuch.
Republican leaders have warned they may use the "nuclear option" to change Senate rules to weaken the filibuster of Supreme Court nominees -- meaning Gorsuch would need just 51 votes to be confirmed -- if that's required to get him approved.
At the committee, each witness gets five minutes to speak, and committee Chairman Chuck Grassley said he doesn't expect senators on the committee to ask a lot of questions.
Witnesses include a range of supporters, like retired federal judges, law professors and former law clerks of Gorsuch's. One of them is Judge John Kane, currently a senior judge in the US District of Colorado, where Gorsuch lives.
The Democrats on the committee are also putting forward witnesses, many of whom are representatives from nonprofit groups, including the Sierra Club and the National Women's Law Center.
Another witness is Jeff Perkins, whose son with autism was at the heart of a lawsuit resulting in a high-profile interpretation by Gorsuch in his current role as a federal judge for the 10th Circuit Court of Appeals.
That interpretation was reversed by the Supreme Court on Wednesday and it became a topic of questioning by Democrats in Gorsuch's hearing.
Gun control advocate Sandy Phillips, whose daughter died in the Aurora movie theater massacre, is also slated to testify.