Senators are grilling top intelligence and election officials Wednesday on Capitol Hill, as they continue to investigate how to better secure voting systems in the U.S.

The hearing before the Senate intelligence committee comes a day after the panel released a list of recommendations to enhance security, including improving communication between the Department of Homeland Security and state officials, "rapidly" replacing aging voting machines across the country and passing legislation in Congress to get states more money to improve cybersecurity.

The hearing is part of the committee's ongoing investigation into Russian interference in the 2016 election. Russian operatives targeted the voting systems of at least 21 states leading up to the 2016 election, according to DHS, and were able to successfully hack into at least one. There is no evidence, however, that any votes were changed.

"The Russians were relentless in attempting to meddle in the 2016 elections and they will continue their efforts to undermine public confidence in Western democracies and in the legitimacy of our elections," said Sen. Susan Collins, R-Maine, during a Tuesday press conference announcing the committee's recommendations.

Republican and Democrat members of the Senate intelligence committee have made a vocal effort to keep improving voter security a nonpartisan issue. That comes in stark contrast to the House intelligence committee, which is essentially performing two separate investigations into Russian interference.

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