The normally mild-mannered Bennet erupted in a fiery speech, saying, "These crocodile tears that the senator from Texas is crying for first responders are too hard for me to take."
Bennet noted that Cruz single-handedly shut down the government in 2013, at a time when Colorado was flooded.
His voice rising to a shout, Bennet said eight people were killed and many homes and businesses destroyed because of the flooding. "And because of the senator from Texas, this government was shut down for politics," delaying relief efforts, Bennet said.
Cruz, who led a 16-day government shutdown in a failed bid to derail funding for the Affordable Care Act, said Bennet "spent a great deal of time yelling (and) attacking me personally," adding that he has never "bellowed or yelled at a colleague on the Senate floor, and I hope I never do that."
Bennet shot back that, unlike Cruz, he never called someone a liar on the Senate floor. Cruz famously accused Senate Majority Leader Mitch McConnell of lying to him during an extended tirade in 2015.
Cruz, for his part, said Bennet and other Democrats opposed the wall merely because of Trump. "They really, really, really, really don't like this man," Cruz said. "But just because you hate somebody doesn't mean you should shut the government down."
The spat between the two senators came as the divided Senate defeated competing Democratic and Republican plans to end the 34-day partial government shutdown.