It is in the interests of no one—other than Trump, his hangers-on, and certain media outlets with die-hard audiences—for a significant number of Republican legislators to keep pretending that Biden won a “stolen victory.” Democrats do not want it, because they will need Republican cooperation to govern effectively. Even if Republicans do not hold the Senate after the Georgia run-off, the Democratic majorities in both chambers will be razor thin and they will need support.
Republicans, meanwhile, should not want their party to cling to the conspiracy theory. No party can thrive if its animating principle rests on such shaky ground. But even if they thought it was true, or might be true, they do not want to remain stuck there because they cannot achieve anything without Biden. They need him to sign legislation; how do they work with him without addressing their claim that he pulled off the biggest fraud in American history? Even if they wanted to ignore it, would Trump let them?
Republicans cannot pull themselves out of this hole without help.
Help is available, in the form of a time-honored mechanism that has lifted American leaders out of other political pits so that they can get back to the business of governing, with all the normal political haggling associated therewith.