US Republican Senator Ted Cruz warned Friday that his party could face a bloodbath of Watergate proportions in next month's election if voters are pessimistic about President Donald Trump's handling of the economy and the pandemic.

Iran Press/America:  "I am worried... It's highly volatile," Cruz, a staunch Trump ally, although he noted that Trump could win re-election -only- if voters feel the country is recovering from the pandemic-driven economic crisis.

"If people are going back to work, if they're optimistic, if they're positive about the future, we could see a fantastic election -- the president getting reelected with a big margin, Republicans winning both houses of Congress," Cruz told CNBC television.

But he also spoke of the possibility of landslide losses similar to those in 1974, when Democrats expanded their majorities in the House and Senate in the first election following the Watergate scandal and the resignation of Richard Nixon.

Democrat Jimmy Carter won the White House in 1976 in the first post-Watergate presidential election.

"If on election day people are angry and they've given up hope and they're depressed... I think it could be a terrible election," Cruz added.

"I think we could lose the White House and both houses of Congress, that it could be a bloodbath of Watergate proportions."

Trump has trailed his Democratic rival, Joe Biden, in nearly every major poll this year.

Democrats are widely expected to keep the House in the November 3 election.

Republicans hold a 53-47 advantage in the Senate, but that majority is under threat with Republican senators in several battleground states trailing in polls behind Democratic challengers.