Here's a run-down of Texas' suit against MI, WI, PA, and AR @FDRLST. It is the basics of what you need to know. 1/ https://thefederalist.com/2020/12/09/6-things-to-know-about-texass-supreme-court-petition-over-2020s-messed-up-election/
2/ I had previous analyzed the PA constitutional problems in depth and this analysis translates perfectly (albeit without the standing and remedy issue addressed). Also, if you haven't read, https://thefederalist.com/2020/11/12/pennsylvania-mail-in-ballot-snafu-is-ripe-for-the-u-s-supreme-court-to-intervene/
3/ that piece, it was an exclusive with long-term PA election chair and it adds substantially to the texture of the PA violation alleged in Texas case.
4/ And here's the solution Texas wants the S.Ct. to mandate...something the state legislators could do on their own if they weren't a bunch of pantywaists. https://thefederalist.com/2020/11/19/state-legislatures-must-investigate-fraud-and-choose-electors-accordingly/