"Yet, amidst all the three-dimensional chess, the irony is that nobody knows how justices will perform until they don the robes. Republican President Dwight Eisenhower named Earl Warren and William Brennan, who helped tilt the court leftward for a generation".
Yeah well nobody knew how Warren would do on the court as he never served as a judge before (he was a three-time California governor, and republican candidate for vice-president in 1948). As to Brennan, Ike asked for it, as he wanted to nominate "a Catholic, Democrat from North-East" to increase his chances during re-election. Now what could you possibly expect from a democratic judge from New England????
For me much more shocking were people like Harry Blackmun (who was proposed to president Nixon by Chief Justice Burger) and David Souter (who was proposed by Sununu). Now THEY (unlike Brennan for example) were supposed to be conservatists...
For all the hoopla about being a Republican, Ike was a social liberal. In fact, it wasn't a given that he would run as an "R". Plus, at that time, the Republican party, as it was dominated by the striped-pant, Rockefeller bunch, was the liberal party. Don't forget that JFK's SC appointment (White) was one of the most conservative justices on the bench for a generation, and dissented in Roe v Wade.
So in those days, when the Republicans appointed a judge, there was no guarantee they were looking for someone conservative.