Director of National Intelligence Dan Coats, FBI Director Christopher Wray and other officials "made it clear there are active threats and they're doing everything they can" to stop them, said Rep. Debbie Dingell, D-Mich. Dingell called the closed-door presentation "very impressive" and said the issue was "one we all need to take seriously."
Coats, Wray and other officials, including acting Homeland Security Secretary Kevin McAleenan, met separately with the House and Senate in classified briefings at the Capitol. Democrats requested the sessions as they press legislation to keep Russia and other foreign adversaries from interfering with the U.S. political system.
House Minority Whip Steve Scalise, R-La., called the briefing helpful and said it reinforced the importance of remaining vigilant against outside threats to U.S. elections.
Federal agencies "continue to learn from the mistakes of the 2016 election, when the (Obama) administration was flat-footed in their response" to Russian interference, Scalise said. "We need to stay vigilant."
Special counsel Robert Mueller laid out details of Russian interference in the 2016 election in his report earlier this year, and lawmakers from both parties have warned that the Russians are likely to try to interfere again in 2020.
Democrats say Senate Majority Leader Mitch McConnell has blocked bipartisan bills to address election security, and they pressed for the briefings as a way to force his hand.
McConnell, a Kentucky Republican, said he welcomed the briefings. The "smooth and secure execution" of the 2018 midterm elections "was not a coincidence" and showed the success of measures the administration has already taken, he said.
While acknowledging that Congress may need to act, McConnell said he's skeptical of Democratic-passed bills on election security, saying they give too much control over state and local elections to the federal government.
Democrats "have twice passed bills aimed at centralizing election administration decisions in the federal government, in part on the hope that election attorneys — not voters — will get to determine the outcome of more elections," he said Wednesday.
Democrats disputed that and said urgent action is needed to guard against Russian interference.
"We know that nefarious foreign and domestic actors continue to meddle in our democratic systems, and we've been put on notice that previous efforts were only trial runs presumably for our next election in 2020," said Rep. Zoe Lofgren, D-Calif., the chief sponsor of the House election security bill.
The FBI and other law enforcement "definitely upped their game in 2018," said Virginia Sen. Mark Warner, the top Democrat on the Senate intelligence committee. "But the Russians and others will be back."
While national security officials "are working their hearts out," they were not helped when President Donald Trump joked about election interference with Russian President Vladimir Putin at the G-20 summit, Warner said. Congress also must act, Warner and other lawmakers said, as they urged bills that would create a paper ballot system to back up election machines and impose sanctions on foreign countries that interfere with U.S. elections.
National security officials said in a statement Wednesday that election security is a top priority and that officials are taking a "whole-of-government approach" to securing the 2020 elections, along with state, local and private sector partners.
A senior administration official said there have been about two dozen policy-coordinating meetings on the topic in the past year and Trump has been briefed on at least two occasions.
Despite his joking request to Putin — "Don't meddle in the election" — Trump takes the issue seriously, the official said. The exchange with Putin has not affected the administration's work on the issue, according to the official, who was not authorized to publicly discuss the issue and spoke only on condition of anonymity.
Sen. Marco Rubio, R-Fla., who has co-sponsored a bill imposing sanctions on foreign governments that interfere with U.S. elections, said the Congress must "do everything possible to secure our election systems." His bill, co-sponsored by Sen. Chris Van Hollen, D-Md., would ensure that "Vladimir Putin — or whoever — knows that if they do this again ... what the price will be," Rubio said.
Senate Democratic leader Chuck Schumer of New York said the classified briefing was important but "by no means sufficient."
Congress must "debate and adopt measures to protect our democracy and preserve the sanctity of elections," Schumer said. He accused McConnell of doing "nothing when it comes to one of the greatest threats to our democracy: that a foreign power would reach in and interfere (with U.S. elections) for its own purposes."
The bill approved by the House would require paper ballots in federal elections and authorize $775 million in grants over the next two years to help states secure their voting systems. It also would prohibit voting systems from being connected to the internet or wireless technologies and tighten standards for private companies that provide election infrastructure.
McConnell said again Wednesday that the GOP-led Senate is unlikely to vote on the bill.
"It's interesting that some of our colleagues across the aisle seem to have already made up their minds before we hear from the experts that a brand-new, sweeping Washington, D.C., intervention is just what the doctor ordered," he said.