WASHINGTON (REUTERS) - "I think this whole thing is a crock," said Republican Senator Lindsay Graham, who lashed out at Democrats on Sunday (Dec 15) as they make their last-minute pitch as to why Republicans should put partisanship aside and vote to impeach Donald Trump.

Graham, appearing on CBS's Face the Nation, said he had nothing but disdain for the process.

"You're weaponising impeachment and I want to end it," she said. "I don't want to legitimise it. I hate what they're doing."

But what they're doing is their job, countered Democratic Senator Dick Durbin.

"My friend, Senator Lindsey Graham refers to the whole thing as a 'crock.' You know what it boils down to is we may interfere with some tee times here, but we ought to really stand up for the demeanor, the history and the traditions of the Senate in terms of doing this in the proper way," said Durbin.

Meanwhile, House Judiciary Committee Chairman Jerrold Nadler, a Democrat, told ABC's "This Week" on Sunday that lawmakers have a constitutional duty to hold Trump accountable for trying to recruit Ukraine to launch an investigation into his Democratic political rival Joe Biden.

Trump is expected to become the third US president to be impeached when the full Democratic-led House votes on the charges, likely this week, setting up a trial in the Republican-controlled Senate - which has shown little appetite for removing Trump from office.

Senate Majority Leader Mitch McConnell has raised the prospect of conducting a short Senate impeachment trial without calling any witnesses.

Democrats like Durbin say such a move would do a disservice to the Senate.

Said Durbin: "The bottom line is, if we're going to have an actual trial, we should consider evidence."

Separately this weekend, The Washington Post reported that Rep. Jeff Van Drew of New Jersey, an anti-impeachment Democrat, will soon join the Republican Party.

Trump tweeted in response to the news: "Wow, that would be big. Always heard Jeff is very smart!"