WASHINGTON • Sen. Roy Blunt missed a procedural vote on a bill to fight opioid abuse because he was raising money for his re-election in Chicago.

Democrats criticized the senator's absence on the Monday night vote, saying he was putting politics ahead of important policy debates. The procedural vote passed the Senate, 89-0. Blunt detoured through Chicago on his way back to Washington for the fundraiser after appearing earlier in Missouri at a Farm Bureau event.

Among the senators who also did not vote were Sens. Marco Rubio, R-Fla., and Ted Cruz, R-Texas, who are running for President.

The vote was for "cloture," a parliamentary maneuver allowing the debate and a final vote on the Comprehensive Addiction and Recovery Act of 2015. The Senate is expected to have extensive debate and votes on the bill in coming days.

Blunt faces Democratic Secretary of State Jason Kander in the November election.

Will Baskin-Gerwitz, a spokesman for the Missouri Democratic Party, said that Blunt "owes an explanation to the Missouri families affected by this epidemic about why a campaign fundraiser is more important than doing his job and showing up to vote."