If Cheney were to come out against her, he would back up his opinion with solid reasoning. I'd most definately consider his opinion before making my own decision.
But don’t forget—Cheney is a real conservative but he’s been in Washington for multiple decades.
No, I would form my own conclusion using the normal process, then I would look at the opinions of others, even though their opinions are probably influenced to some extent by Washington. Then I would toss their opinion aside.