As with the PA case, whichever judge is assigned to Texas will almost certainly refer it to the entire court for consideration. That's not mandatory, but with a big important case like this, its probable. I believe they need a majority of 5 to take the case. If they don't have 5, it is usually just a one-sentence order indicating they won't take the case, without explanation (as we saw yesterday in the PA case.) In some cases, there will be a dissent or a concurring opinion if a judge wants to explain himself. One recent example is when Nebraska and Oklahoma sued Colorado a few years ago regarding Colorado's marijuana law. The court refused the case, but Thomas wrote a dissent indicating he believes the Court has to take these cases. His theory is that, since SCOTUS jurisdiction is exclusive, they can't refuse or they will leave the complaining state with no venue in which to make its claim. In other words, Thomas believes the SCOTUS' jurisdiction in cases between states is original, exclusive AND mandatory. Alito joined him (
https://www.supremecourt.gov/opinions/15pdf/144orig_6479.pdf). If they both still feel this way, that means there are probably at least 2 votes in favor of taking the case, so they need 3 more.