Difficult to believe that the US Republican Party is STILL in denial

This is fascinating. Over six months after the last US election, a Reuters/Ipsos poll taken on May 7-19 2021 has, found that 53% of Republicans still believe that Donald Trump is actually the "true" president of the USA. 

That's almost a quarter of the voting population. Perhaps even more bizarrely, 3% of Democrats believe that too! Fully 61% of Republicans persist in the belief that the election was somehow "stolen" from Trump. This, mark you, after endless failed Republican legal challenges to the election results, and repeated confirmations that Biden in fact won by some 7 million votes and by 74 electoral college votes.

In the face of this kind of magical thinking, it is hard to know what to think about American politics. If so many people can willfully disbelieve the facts before their eyes, based purely on partisan opinions, how can politicians continue to strive for democratic progress and the welfare of the common man? How can they even care about these people? I know that we are still talking about a minority of the populace, but it's such a large minority that surely it must make politicians think twice about even wanting to continue.