Don't forget; when Bush the Elder put Souter on the Supreme Court, Souter was supposed to be a conservative. As it turned out, he was merely a liberal in disguise.
Souter has transformed from a CINO (Conservative in Name Only) to a pure liberal.
And this plan...pure genius. Kudos!
My little sister was working in the Bush Whitehouse at the time Souter was nominated so I know a little about how this took place. She was Administrative Assistant to Boyden Grey who was President Bush's (41) Personal Legal Council. Amount other things, Boyden Grey's office was charged with developing the vetting criteria that was used by the Administration to pick Supreme Court nominees. There was a big push to avoid another Bork. Bush (41) had little stomach for a fight and was more of a New England liberal Republican then a conservative anyway.
Consequently, one of the main vetting criteria was that the nominee have written few controversial opinions that revealed his judicial temperament and political leanings. The idea was to give the Democrats little to sink their teeth into. The problem with this approach, which has been borne out by history, is that the President who nominated Souter had no idea what he stood for. They perhaps hoped he was a conservative.