There is a lot of difference between Souter and Roberts.
Yes. Roberts was wire tapped and compromised badly. Souter was never wire tapped. They both were liberals.
Gorsuch, IMO, is closest to Sandra Day O'Connor.
Conservatives backing the O'Connor nomination could point to the fact she was a proud, loyal Republican for many years and there were several examples of times she went to bat conservatives and did things we liked when she was Senate Majority Leader in the AZ Senate. However, they have no evidence whatsoever that she was a social conservative or that she was pro-life (and plenty of evidence in her background hinting otherwise), but they said that didn't matter because her "judicial philosophy" was "strict constructionist", so her own views were irrelevant and wouldn't affect her decisions.