There would be a power fight, the party would split, then it might reform around one of them, but that one would end up losing badly since no one of them can replicate what Trump did. Trump spent most of his life building a power base, making unsavory connections (including Putin), creating a persona that his votes could latch on to, and a following of money suppliers and lackeys all willing to throw themselves in front of the train to protect Trump from just about anything. All this simply by Trump being Trump, greedy, lazy, selfish, yet able to con people out of just about anything and draw attention to himself in ways few others could simply because he thrives on attention.
Anyone who tries to replicate this isn't going to succeed. Eventually the voters will rebel and who knows what will happen.