Not only would he lose, but such a lawsuit would likely backfire on him spectacularly.
(I first wrote about this in a Just Security piece.)
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2/ It's generally accepted that the privilege is held by the sitting president, and the Biden administration already said won't assert executive privilege over this material.
Scholar Hungarian scholar Balint Magyar offers a theory that explains why the US held out against the same tactics that caused other countries to collapse into autocracy.
His theory also explains why comparisons across nations don’t always work.
A key error here is that it assumes that the Electoral Count Act is illegal and assumes that states can set aside the laws they have on the books for allocating their electors.
In fact, rules governing the election have to be in place before the election.
The idea was to create chaos and give Trump's claim that he won the election more legitimacy.
He still wouldn't have stayed in the White House because this wouldn't have worked -- but it may have persuaded more people that Biden didn't win, which undermines the government.