Key Senate Republican: 'Mistake' to get rid of filibuster
"The rules have saved us from a lot of really bad policy. ... I know we all are into short-term gratification, but it's a real mistake, I think, from a legislative standpoint," Cornyn, the Senate's No. 2 Republican, told reporters on Tuesday.
Cornyn vowed to oppose getting rid of the 60-vote filibuster for legislation as long as he is in the GOP leadership team. 
Trump, who has previously pushed for nuking the filibuster, said in a tweet on Tuesday morning that voters should either elect more GOP senators in 2018 or get rid of the 60-vote threshold so Republicans can pass legislation on a party-line vote. 
Republicans currently have a 52-seat majority in the Senate, meaning under the current rules they need at least eight Democratic votes to move most legislation. If they went "nuclear" and changed the rules, they could pass legislation with 51 votes.
But Cornyn defended the legislative filibuster in a speech from the Senate floor, noting he was holding a list of 15 examples of when the higher requirement blocked Democrats from passing legislation such as tax increases and climate change proposals. 
He added that keeping the 60-vote requirement intact is "so important." 
"It's really important that in a country as big and diverse as ours with 535 members of Congress that we be forced or strongly encouraged at least to build consensus before we pass laws," he said. 
Cornyn didn't specifically mention Trump's tweet in his speech but noted he had heard some people recently "actually since the election, actually as recently as today, say, well, maybe we ought to do away with the 60-vote cloture requirement." 
Republicans have been under pressure for years from House lawmakers and outside groups to get rid of the legislative filibuster. That pressure has only intensified after they got rid of the 60-vote requirement to end debate on Supreme Court nominations earlier this year. 
Democrats had already lowered the threshold for lower-court and executive nominees in 2013. 
But senators have shown little appetite for getting rid of the threshold for legislation, with members in both parties warning that the move would effectively turn the upper chamber into the House. 
"There's not a single senator in the majority who thinks we ought to change the legislative filibuster, not one," he told reporters last month. "We all understand that's what makes the Senate the Senate." 
"We are asking you to join us in opposing any effort to curtail the existing rights and prerogatives of senators to engage in full, robust and extended debate as we consider legislation before this body in the future," they wrote at the time.