The business interest are the most persistent and well-integrated element of the Republican Party. They don’t just show up for rallies and primaries. They don’t just write checks. They invite these politicians for functions, and what do Republican politicians see? They see the doers who built that. The politicians naturally gravitate toward the priorities of their most visible allies. Upfront amnesty and low-skill guest worker programs are just common sense, but late-term abortion bans are a distraction from the real work of government.
It would be easier if Republican politicians were simply bought. They could always be bought back by the lure of votes. Walker wanted to sell out to immigration restrictionists, but he didn’t know how. Walker didn’t know how immigration restrictionists talked or thought. They were alien to him.
Think about it from the perspective of the Republican office holder. Who looks more reasonable to him? Is it the audience at the local Chamber of Commerce Dinner, or is it the crowd at a Tea Party Rally? I suspect that many Republican politicians sincerely see their own party as composed of sober businessmen, plus crazy people wearing tricorne hats, plus crazy people waving fetus selfies, plus crazy people jabbering about Mexicans. The behavior of establishment Republican politicians can be seen as trying to placate/gull the various crazies so that the real work of the business lobbies can finally get done.