The American Constitution Society urged fellow legal liberals on Wednesday to help obstruct President Trump's judicial nominees.

Leaders of the left-leaning legal organization held a briefing call aiming at mobilizing liberal opposition to Trump's nominees. Ronald Klain, an ACS board of advisers member, said on a briefing call with the liberal legal community that liberal lawyers and ACS members need to be "forceful" in their efforts to encourage Democratic senators on the Judiciary Committee not to return "blue slips," effectively blocking Trump's nominees.

Under the Judiciary Committee's blue slip tradition, a state's senators are consulted by the governing administration before a president nominates a judge from that state, no matter the party affiliation, according to a Congressional Research Service report detailing the blue slip policy. A senator can employ the blue slip tool to block a nominee from the senator's home state whom he or she opposes from receiving a Senate Judiciary Committee hearing or vote.

Klain detailed the high stakes of the pending judicial nominations by noting that Trump has moved faster than his predecessors at nominating and confirming federal judges and called Trump's pace "extraordinary."

"The people he's naming to the bench will be there for a very, very long time," Klain said Wednesday. "If you look at the early court of appeals nominees under President Obama, their average age was 56. President Trump's first nine court of appeals nominees' average age [is] 48. That eight years may not seem like much but what that really means is his nominees will serve two more presidential terms than President Obama's will and people [Trump] is putting on the bench might well be defining our law to the year 2050 and beyond."

Christopher Kang, former deputy counsel to President Obama and ACS board of directors member, said liberals must not accept conservatives' complaints about their efforts at obstructing the judicial nominees.

"It's easy to let ourselves buy into this narrative that maybe Democrats really are obstructing and we should be happy about that," Kang said. "And the reality is unfortunately we haven't been able to stop him enough because of how much work and capital not just President Trump, but Senate Republicans have put into judicial nominations."

Lena Zwarensteyn, ACS strategic development director, stressed the dire situation for Democrats and told liberals on Wednesday that, "the federal judiciary is in jeopardy."

ACS' Wednesday briefing comes after the Senate Judiciary Committee met to consider two of Trump's federal appeals court nominees earlier in the afternoon and following Democratic Minnesota Sen. Al Franken's decision on Tuesday to refuse to return a blue slip on one Trump judicial nominee, David Stras.