Washington (CNN) Virginia Democratic Sen. Mark Warner predicted Sunday that observers will eventually believe President Donald Trump mishandled the standoff that has created the ongoing government shutdown.

"I think history will show that Donald Trump, the supposed great dealmaker -- and I'm working on a piece on this -- that business schools and management consultants will look back for years and say this was the most inept negotiation," Warner told CNN's Jake Tapper on "State of the Union."

Warner, the top Democrat on the Senate Intelligence Committee, said Trump has not given key Republicans enough room to negotiate and has not "allowed any win-win circumstance" as he continues to demand Congress appropriate money to pay for his proposed border wall with Mexico.

"He boxed himself in a corner," Warner said. "He didn't empower his negotiators, like the vice president or (South Carolina GOP Sen.) Lindsey Graham or (Senate Majority Leader) Mitch McConnell."