Members of Congress have several major decisions to make after the special counsel Robert Mueller’s investigation into Russian interference in the 2016 election. Whether to pursue an impeachment inquiry is the one that’s gotten the most attention — and reasonable people can disagree about that. But Mr. Mueller’s findings leave no room for debate about the need to address the legal and institutional deficiencies that allowed a foreign adversary to tamper with America’s democracy.

From cyberattacks on state voter systems to disinformation campaigns waged on social media to the hacking of materials belonging to a major political party, Mr. Mueller made plain that the country’s electoral infrastructure remains vulnerable to attack. If the problems are left unaddressed, nothing will stop Russia or other actors from once again undermining free and fair elections in the United States — and they seem to be gearing up to try to do just that.

The Democratic-led House recognized these challenges earlier this year by passing H.R. 1, a sweeping pro-democracy bill that took stock of the lessons learned about 2016. Among its key provisions are funding for states to switch to paper ballots and improve cybersecurity protocols, as well as transparency measures for political ads on social media platforms.

Mitch McConnell, the Senate majority leader, has indicated that he has no intention of bringing the bill up for a vote. However, a number of his Republican Senate colleagues, including South Carolina’s Lindsey Graham and Oklahoma’s James Lankford, have introduced or co-sponsored their own proposals to strengthen the nation’s voting systems or to respond to circumstances described in the special counsel’s report.