Ed Whelan has this note regarding how Judge Sotomayor was selected by the George HW Bush White House to be a district court judge:
. . . when President Bush nominated Sotomayor to the district court in 1991, the New York senators, Moynihan and D’Amato, had forced on the White House a deal that enabled the senator not of the president’s party to name one of every four district-court nominees in New York. Sotomayor was Moynihan’s pick. I am reliably informed that Bush 41’s White House nonetheless resisted nominating her because she was so liberal and did so in the end only as part of a package to move along other nominees whom Moynihan was holding up.
So not only did Bush put Souter on the Court, he paved the way for Sotomayor. And Whelan indicates she will be a far left-wing voice.
But as I said before, her lack of intellectual firepower compared to Scalia and Roberts means she won't be an influential one (*cough*Stevens*cough*).