“I have bent over backwards to try to listen and accommodate and modify my plan,” Collins said. “I tried to explain to [Democrats] some of the different realities that I’m dealing with in my caucus as well. It’s a delicate balance to keep enough Republicans on board as well as attract Democratic support.”

The frustration clearly boiled over on the Senate floor on the 12th day of the shutdown as Collins and Sen. Patty Murray (D-Wash.) engaged in a heated back-and-forth over the Democratic leaders’ rejection of Collins’ plan, according to several sources who witnessed the exchange.

Murray, the No. 4 in Senate leadership, pointedly told Collins that it was unacceptable to lock in cuts at the sequestration spending levels. Collins scoffed at the Democratic position, arguing she had worked to find a solution that both sides could accept…

Indeed, top Senate Democrats made their distaste for the Collins plan clear early Saturday. Leaders privately began to encourage Democratic senators who were working with Collins to back away, arguing that it was a bad deal for their party in the high-stakes impasse with the GOP, several sources said.