The fear is that he might appoint a Kennedy or a Souter. IKE appointed Brennan because his business buddies told him that though a Democrat he was pro-business. Turned out to be one of Ike’s real regrets. A President has no control over a justice once he is appointed. Trump is simply NOT a conservative. He has invoked the name of Bill Buckley, but Buckley could not stand the guy. said he was a demagogue. They come in several styles, of course. Demosthenes was a demagogue. Trump is a rabble-rouser.
I have the same news for you that I have for many other posters on this thread: there is no perfect candidate. Every candidate, even Cruz, would make critical errors in office. Every Republican president in the past century since Eisenhower had justices turn left on him. Now that the leftists have packed the law schools with marxists and filled the federal judiciary with activists, the pipeline itself is corrupted and finding a reliably conservative justice will be difficult for ANY president, even Cruz. Look what happened with Roberts, whom Cruz admired, at least in part.
The biggest issue is that any Republican wins at all.
After that, the next biggest issue is that the economy and the debt are ready to collapse us, and must be addressed forcefully with knowledge. Trump forcefully and knowlegeably called out these difficult issues -- first before anyone else -- and has the skills to address them.
As for his SCOTUS picks, many posters are ranting that he knows "nothing" about the Constitution and blah blah blah -- failing to understand that he sees the role of Chief Executive properly, which is to develop a vision and plan and see that it gets executed by a competent team. SCOTUS appointments are an issue where he would absolutely take advice from deeply knowlegeable team members, and it would greatly surprise me if he did not also ask Ted Cruz to be involved in the selection process.