In one of several Pennsylvania cases, Trump attorneys actually signed a legal document in which they stated,
“Petitioners do not allege, and there is no evidence of, any fraud in connection with the challenged ballots; Petitioners do not allege, and there is no evidence of, any misconduct in connection with the challenged ballots; Petitioners do not allege, and there is no evidence of, any impropriety in connection with the challenged ballots; Petitioners do not allege, and there is no evidence of, any undue influence committed with respect to the challenged ballots.”

Why did they do it?
As members of the bar association — the state entity that grants attorneys their license to practice law — lawyers have a professional ethics obligation “not to abuse legal procedure” by filing “frivolous” claims. Rule 3.1 of the Model Rules of Professional Conduct, some version of which applies in all states, forbids a lawyer from bringing a claim or argument “unless there is a basis in law and fact for doing so that is not frivolous.”

[...]lawyers must be able to honestly represent to the court that they have a basis for believing they have a path to getting relief either based on existing law or “a good faith argument for an extension, modification or reversal of existing law.”
Violating this requirement could expose the lawyer to sanctions from the state bar, which could range from a reprimand to a fine to a license suspension. More practically, it can erode courts’ confidence in the lawyer’s reliability and damage the lawyer’s professional reputation.
In Trump’s case, this means his attorneys can only say the election was stolen if they know of actual, credible reports of systematic fraud.

https://truthout.org/articles/trumps-election-fraud-claims-dont-appear-in-result-challenge-lawsuits/

"From a controversial international tour by the secretary of state, to shutting down emergency lending programs at the Fed as the pandemic accelerates, to continuing to do damage to the climate, Trump, with the consent of the GOP, is trying to sabotage Biden’s chances at a recovery every way he can. But it’s the nation itself that will suffer — and Trump and his administration don’t care. As Adam Serwer wrote in 2018 of Trump’s policies, “the cruelty is the point.” Trump is doing his best to accelerate it in his final weeks in office."

https://truthout.org/articles/trump-is-trying-to-set-yellen-and-biden-up-to-fail-as-he-sabotages-the-economy/

"On Tuesday, Trump tweeted that he and his legal team had a “big lawsuit” planned which would “[spell] out in great detail all of the ballot fraud and more.” So far, however, nearly all of Trump’s legal filings alleging fraud have been dismissed, with judges pointing to the lack of proof of fraud or election rigging of any kind. There’s no sign or proof from Trump that this new lawsuit would be any different."

https://truthout.org/articles/trump-tweets-bogus-poll-backing-his-refusal-to-concede

Before he leaves office, Trump is looking to give the GOP one last anti-democratic gift: an intentionally skewed congressional apportionment count, so Republicans can entrench their anti-majoritarian power.

https://jacobinmag.com/2020/11/donald-trump-anti-democratic-congressional-apportionment-count-republicans/

Georgia Deputy Secretary of State Jordan Fuchs said the allegations in the lawsuit “are false and irresponsible.”

“Texas alleges that there are 80,000 forged signatures on absentee ballots in Georgia, but they don’t bring forward a single person who this happened to. That’s because it didn’t happen,” Fuchs said.