Bob Taft was the leader of Congressional conservatives who fought the New Deal and tried to roll it back. Unfortunately, we’re still stuck with a good bit of it.
Eisenhower was the Eastern Establishment’s candidate. Dewey and Warren supported him, and he’s the one who put Warren on the Supreme Court (Brennan too.)
Taft was not an isolationist, but had a foreign policy vision somewhat similar (in its time) to President Trump’s, and conservatives are at best reluctant internationalists.
The majority of Republicans including Thomas Dewey were happy to have the hero of WWII victory in Europe as their candidate.
Eisenhower didn't know Brennan and his decision to nominate him to the Court was influenced by a speech which Brennan read but hadn't written, and which didn't reflect Brennan's actual views.
You're implying that Eisenhower was a fan of Earl Warren which is known not to be the case.
https://www.theatlantic.com/magazine/archive/2018/04/commander-v-chief/554045/
"Appointments he later regretted: Eisenhower famously said that his biggest mistake had been selecting “that dumb son of a bitch Earl Warren.” Or so one of his early biographers claims; the remark has come into question. Warren himself wrote that the president was known to have described his appointment as “the biggest damn fool thing I ever did.” Another version has it that when asked whether he had ever made any mistakes, Eisenhower replied, “Yes: two. And they are both sitting on the Supreme Court.”