The Republicans have been doing what the Democrats have been doing for years: battle it out at the grassroots. From Mollie Hemingway at thefederalist.com:

Against a hostile propaganda press, many Americans have poured themselves into restoring election integrity — and it’s working.
If Republican candidates do as well as expected on Tuesday, they can credit the new, widespread, and coordinated effort to begin securing U.S. elections, helping give candidates the best opportunity possible to win a fair fight in the new voting environment of mail-in balloting.
The Republican National Committee, other party entities, and dozens of public interest election nonprofit groups built over the last two years a multimillion-dollar election integrity infrastructure that passed laws improving voter ID and other election security measures, defended those laws from legal attacks by Democrats, and sued states and localities that failed to follow the law. They also recruited, educated, trained, and placed tens of thousands of new election observers and other workers throughout the long midterm voting season.
2020’s Wake-Up Call
The 2020 election was a massive wake-up call for many Americans on the right. In the months leading up to it, Democrats forced through changes to hundreds of laws and processes governing how elections are conducted.