On Wednesday, Sen. Scott Brown (R-Mass.) became the first Republican senator to express support for a federal ban on assault weapons. 

"What happened in Newtown where those children were subject to that level of  violence is beyond my comprehension," he told a Massachusetts newspaper.

Brown noted that he supported an assault weapons ban when he was a state legislator in Massachusetts and that the nation needs a broader debate regarding mental health issues.

Brown lost his reelection bid last month, so it is unlikely that he still will be in the Senate when legislation prompted by the Newtown, Conn., elementary school shooting is considered by lawmakers.

Sen Dianne Feinstein (D-Calif.) said this week that she will reintroduce a ban on the weapons when the new Congress begins in January. Numerous Democratic senators who strongly back gun rights have announced that they are open to a discussion of new restrictions. 

Ed O’Keefe is covering the 2016 presidential campaign. He's covered presidential and congressional politics, Congress and federal agencies and spent a brief time covering the Iraq war.