By Robert W. Ludwig ( March 15, 2016, 10:17 PM EDT) -- In another pledge, threatening another shutdown, this time of the Senate and U.S. Supreme Court, Judiciary Committee Republicans vowed in February not to hold hearings this year on any nominee to succeed Justice Antonin Scalia. Sen. Ted Cruz, a committee member running for the presidency, argued "we're one justice away from the Second Amendment being written out," referring to a right to guns newly found in District of Columbia v. Heller, 554 U.S. 570 (2008). Three days before the pledge, an Uber driver in Kalamazoo killed six in the 42nd mass shooting this year, on pace with daily mass shootings in 2015. Two days after, a rampaging Kansas driver left four dead, 18 wounded. Two days later, a Virginia man shot his wife and three police officers, miles from Capitol Hill....