Sen. John Cornyn (R-Texas) on CBS's "Face the Nation" Sunday dismissed new impeachment evidence obtained from Lev Parnas, an indicted associate of Rudy Giuliani, stating that there is "no question that there have been a series of grifters" who have associated themselves with the Trump campaign.

The exchange:

BRENNAN: "Doesn't it trouble you that [Parnas] was working so closely with Rudy Giuliani, who was acting on the president's behalf and saying he was acting on the president's behalf?"

CORNYN: "Well, there is no question that there have been a series of grifters and other hangers-on that have associated themselves with the president's campaign or claim to have special relationships with the president, but this is not the issue that the Senate is going to be deciding."

Why it matters: Parnas has claimed that the campaign to pressure Ukraine to announce an investigation into the Bidens was carried out with President Trump's consent and awareness. "President Trump knew exactly what was going on," Parnas told MSNBC last week.

Yes, but: Many have questioned whether Parnas is a reliable narrator because he's been indicted for violating federal campaign-finance laws.

Cornyn criticized Democrats for wanting to "rest their case" on someone "under indictment in the Southern District of New York with extensive ties to Russian oligarchs and organized crime."

The big picture: At least five former Trump campaign advisers or associates have been convicted or pleaded guilty to various crimes in the last three years.

Giuliani, the president's personal lawyer, is reportedly under investigation for his business dealings, including his activities in Ukraine.

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