“Each house shall be the judge of the elections, returns, and qualifications of its own members”
Constitution of the United States, Article I, Section 5
The Republican House of Representatives can adjudicate any matter which may present itself during a federal House candidate election, such as conducting a signature verification.
The Republican House might have special masters appointed by each state Republican party (and Democratic party if it wishes to participate) adjudicate (and validate) each in-person voter and each ballot that comes in by mail or is to be dropped into a drop box.
The adjudications would need to be done right then and there in most cases. That would require preparation.
The DoJ will sue the pants off the first state that tries it and the case will be in courts for years or at least until the state gets a Democrat AttyGen and signs a consent decree. It is a good idea but the Dems will amnesty all 20 million illegals right after the next stolen election and grant all of them citizenship and that will be the effective end of our Republic and our democracy. The socialists will then proceed to wreck the economy, the first and fourth amendments, the supreme court, and whatever other law or institution stands in their way. Eventual amidst the ruin and general discontent asmall minority will rise up and hang them all from lamp posts but that could be generations down the road. Cuba proves the staying power of bad ideas and how accustomed to tyranny the people can become..