It's not good politics to violate the Constitution. 

Via National Journal:

To understand why gun-control efforts are so politically difficult, it’s instructive to look at certain Democrats—the red-state variety who haven’t joined their national brethren in denouncing the National Rifle Association. 

Six red-state Senate Democrats representing largely rural states are up for reelection in 2018, and not one came out for more gun control in the wake of the Vegas killings. 

National polls further explain the Democrats’ reticence:

48 percent of Americans said they had a gun in their household, according to an August NBC News/Wall Street Journal survey—the highest total since the pollster began asking that question in 1999.

A 50 percent majority in the same poll said they worry that government will go too far in restricting the rights of citizens to own guns.

Two national polls conducted in 2016 (NBC/WSJ and Quinnipiac) found the NRA with net-positive favorability scores, despite the barrage of negative publicity. This is far from a slam-dunk political issue.

Read more here.