(CNN) Republican Sen. John Cornyn Wednesday blasted the socialist vision of Democratic presidential candidate Bernie Sanders and said it's critical Republicans keep control of the Senate to be a "firewall" against the Vermont senator's policies in case he's elected.

"I think in this contentious political environment, the most important message I think for my constituents is we need to make sure we hold the Senate majority so we can be a firewall against bad policies if Bernie Sanders gets elected," said Cornyn, who is running for a fourth term in Texas.

Emerging from a closed retreat on Capitol Hill -- where top campaign aides to President Donald Trump briefed GOP senators on their reelection efforts, and the senators had a detailed discussion about this year's tight Senate races -- Cornyn described Sanders as a "Trojan horse," whose views may sound good to some on the surface but would actually destroy America.

"I never thought we'd be having a referendum on the free enterprise system versus socialism but that appears to be where we are headed," Cornyn said. "I just think we need to remind people that we don't want the United States to look like Venezuela, or any of these other failed experiments and socialism."

Cornyn was asked if Republicans might be helped on Election Day if Sanders were the Democratic nominee.

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