I don't believe that Trump is still the leader of the Republican party, his rallies are only taking place in safe secure mostly ex-Confederate states and not drawing huge crowds. He's the leader of the party in those states but has no national coat tails.
Just as Palin's campaign for Congress has resulted in a collective yawn, and she will lose badly in the primary, so lies the direction of Trump's political future. The problem is that even left leaning sites continue to feature an overwhelming focus on all things Trump because those stories provide the clicks that drive ad revenue. And that leaves the unfortunate impression that he's still relevant.
Politically, Trump is toast. And when the 1/6 Committee starts televised hearings this fall, the Republicans will see their entire house of cards collapse.