George Will is an opinion columnist. How he forms his opinions are his business, not ours. He is not on the public’s dime; he is not a news reporter who has made claims of being objective.
Try this thought experiment: you’ve just read a column, by Will or any other opinion columnist for that matter. You agree with it. But wait: you find out that the columnist has been influenced by a person or group you dislike.
Oh no; you’ve got GWICD: the George Will internal cognitive dissonance syndrome. You hold two mutually contradictory opinions on a George Will column at the same time. Must change to conform to your dislikes, never mind that you agreed with the column.
Judge his work on its merits, or lack thereof. It is opinion; it is not valid to criticize an opinion writer for having one. Or for changing his opinion, regardless of why.
Worst case? A columnist is on the payroll of some group and doesn’t disclose that fact. Again, so what? Read his columns, judge them on their merits. Not by who may have taken the columnist to lunch.
If you think that Will is too soft on someone (or, too hard), you’re free to a) disagree, b) send George a scathing letter or email, c) stop reading him.