No, you're extrapolating here. People voting for Trump to be president doesn't in any fashion imply that those people would support him illegally hanging on to the position in opposition to a legitimate election.
And yet his approval rating has improved since the election.
https://projects.fivethirtyeight.com/trump-approval-ratings/
If there were any truth to your suggestion, clearly his ratings would have tanked, and we see the exact opposite.
They don't see it as illegal, either.
Ah, so much easier than presenting evidence.
You claim Trump's support is shrinking, using the exact same amount of evidence behind Trump's lawsuits - zero.
If you don't wish to just retract your claim, present evidence that shows there's any shrinkage to his support.
Remember, this is a bloke who has openly and proudly claimed to pay as little tax as possible, admitted to sexual assault, abused a Gold Star family and enabled Proud Boys and racists, among a huge litany of crimes again mankind. Why do you think these people who have stuck with him all the way will suddenly desert him?
They believe what he's saying about the election being stolen and will continue to support him, and going by the early poll results, possibly even more than they did last month.