The only thing we can trust any of these people to do is that each one of them (like each one of us) will do what they perceive is in their best interest.
Our job then is to try to determine, based on their past history, which one of these people’s self interest best coincides with ours.
It’s that “past history” thing you cite some here use try to use for their candidates who have an equivocating position on illegals with respect to amnesty, pathways, high-standard and all that double-talking gobbledygook.
It’s called “squirrel!”