Sen. Mark Warner, D-Va., said that even if voters are motivated by a strong economy, "many people realize we need a check on this president." And Sen. Chris Van Hollen, D-Md., said the party still has a "very narrow path" to a Senate majority despite facing the toughest Senate political map in 60 years.

McDaniel and Warner appeared on CBS' "Face the Nation," Tillis appeared on "Fox News Sunday," and Van Hollen appeared on "Fox News Sunday" and ABC's "This Week."

ELECTION SECURITY

Warner, the ranking Democrat on the Senate intelligence committee, said that people should "go out and vote with confidence" but that the White House has "frankly held back" on ensuring the election will be secure.

The Virginia Democrat faulted the White House for opposing an election security bill that would have ensured that every polling station had a paper ballot to audit after the election. And he questioned Trump's decision to eliminate the role of cybersecurity coordinator on the National Security Council.

Trump received a briefing on election security last week. US intelligence agencies jointly asserted last month that Russia, China, Iran and other countries are engaged in continuous efforts to influence American policy and voters in the upcoming elections and beyond.