The 16-day government shutdown hurt the U.S. economy at a difficult time, the Democratic Virginia senator said.
Two positive aspects emerged from the 16-day government standoff: A budget conference for the eventual fiscal deal and the lesson that shutting down the government is a horrible idea, Sen. Tim Kaine of Virginia said.
"It has been an unnecessary pain," the Democrat said Thursday on Morning Joe. "It has been damaging to the economy, to the people, to our reputation."
Kaine was forced to furlough 37 of his 42 staff contractors and federal workers during the closure. They returned to work on Thursday.
The shutdown cost the U.S. economy $24 billion, according to an analysis from rating agency Standard & Poor's.
"We're chipping away at U.S. economic dominance around the world; it's a very dangerous thing to have happen," CNBC's Eamon Javers said on the show. "I don't think American politicians fully understand that because they have grown up in a world where that is the case, and they can't even imagine it going away."
Political tensions in the country will increase, though, as Americans continue to worry about their economic future, Javers added.
Although it ended, the "toxic" shutdown will have a major effect on November statewide and House legislative races, especially in Virginia, Kaine said.
"The expectations are low," he added, "but we fail every other way."