If Reid tries to protect endangered Democratic incumbents from voting on gun-control measures, he could be helped by Senate Judiciary Committee Chairman Patrick Leahy (D-Vt.), which has jurisdiction over the issue. Leahy has a history of support for gun owners’ rights and has called for a practical approach to new legislation.

Senate sources believe gun-violence legislation will come up for a vote in the Senate, but the question is whether an assault-weapons ban or curb on high-capacity ammunition will be included in the base bill or offered as amendments to the legislation. Leahy will decide that.

It would be much easier for Baucus, Hagan and other vulnerable Democrats to vote against gun-control measures if they are amendments instead of part of the main bill.

Schumer, a proponent of gun control who is also responsible for Democrats’ policy and message strategy on the Senate floor, suggested Wednesday that expanded background checks would be the main component of a bill.