The Democratic fear is that once the moment passes and attention shifts away from election law to spending issues and now a contentious Supreme Court nomination, the talks will fizzle and Democrats will be left with nothing to show for their voting rights drive, even as the 2022 midterms loom and the 2024 election is just over the horizon.

But leaders of the talks that now include at least 16 senators divided between Republicans and Democrats say they are substantive, gaining momentum and could produce legislation that might prevent another Jan. 6-style confrontation by focusing on fixing the deficiencies in the 135-year-old Electoral Count Act.

They point to the bipartisan infrastructure measure that many of the same lawmakers were able to produce last year as their model for negotiations, and as proof that compromise is still possible.

“I’m encouraged by the fact that almost every day, someone calls me and asks to join our group,” said Senator Susan Collins, the centrist Republican from Maine and a leader of the compromise effort. She characterized its members, who met virtually this week, as ranging from “pretty conservative to pretty liberal.”