The lawsuits filed in Pennsylvania and elsewhere are highly unlikely to go anywhere. The most recent complaint filed in federal court in Pennsylvania amounts to virtually nothing. Its core idea, that the different procedures for voting by mail and voting in person constitute an equal-protection violation, is ludicrous.
First, the differences between mail-in and absentee voting were obvious for months and nothing prevented the Trump campaign from suing earlier over this; a late suit now is barred by a legal doctrine called laches, which says that you cannot simply wait until after an election you don’t win to sue over an election problem you could see beforehand.
Further, having different procedures for mail-in and in-person balloting does not create an equal-protection violation. If this claim succeeds, it would mean that voting was unconstitutional across the entire country. The claim is especially weak when voters had the choice to vote using either system. The other claims in the complaint are mostly retreads of issues that have been rejected legally, factually, or both in other lawsuits. There has been no proof of widespread fraud.
Even if some of the claims were to have merit, a strong argument exists that federal courts should not get involved. The Electoral Count Act, passed after the disputed 1876 presidential election, conceives of a state role, not a federal role, for resolving fights over the election, and federal courts will likely want to let states decide. A federal ruling could endanger the ability of a state to submit its Electoral College votes by the December 8 safe-harbor deadline; Congress cannot challenge Electoral College slates submitted by that date.