Despite overwhelming popular support for the Toomey-Manchin background check compromise, the Republican Party voted en masse in the Senate today to kill the bill: Gun Control: Senate Rejects Background Checks Deal.

The Senate has rejected a bipartisan proposal to expand background checks on gun sales, handing President Barack Obama and Democratic leaders a major defeat on one of the key pieces of the president’s second-term agenda.

The vote was 54-46, with only four Republicans crossing the aisle and voting with the Democrats in favor of the bipartisan proposal by Sens. Joe Manchin (D-W.Va.) and Pat Toomey (R-Pa.). Sixty votes were needed.

The GOP Senators killed this already watered-down bill in full view of a group of Newtown family members.

In a fitting coda to this affair, a number of Newtown family members intend to sit in the gallery to watch today’s voting, a spokesperson for one of the family groups, Sandy Hook Promise, tells me. Among them are Mark and Jackie Barden, whose youngest son, Daniel, was killed in the shooting; Nicole Hockley, who lost her son Dylan; and Jimmy Greene, who lost his daughter Ana.

Family members decided that witnessing today’s events — even if painful — was too important to forego, a source familiar with their thinking tells me. However, there is still some hesitation about having their reaction appear on camera during what would be the first significant defeat of one of their most desired legislative goals, i.e., expanded background checks.