Aren't most of the liberal justices GOP nominees? Souter, Kennedy, Stevens, and O'Connor were nominated by Republicans.
Kennedy and O'Connor are not liberal. They are mushy moderate conservatives. Liberals were foaming at the mouth to attack them as "partisan Republicans" when they voted to stop Gore from having infinite recounts in Florida. O'Connor is the 4th most conservative member of the court and has voted the "right way" on the majority of the issues (property rights, Christian heritage, school vouchers, gun rights, etc.) She's wrong on abortion and a couple of others.
And the only reason we have wussy moderate Kennedy on the court is that the Senate Dems lynched the previous two conservative nominees Reagan put up.
The only real screw ups where Republican Presidents tossed wacko liberals on the court was Ford appointing Stevens and Bush I appointing Souter.