I am trying to point out, you should be promoting your candidate to bring people to him, not deriding and driving people away for being too stupid to realize that they have no choice.
People always have a choice, they can simply choose to tune this entire process out.
I try to do that too ... with those that seem open to hearing some truths and other evidence that Trump is the only logical choice now. Way too many have developed such a case of tunnel-vision that they cannot/will not see the truth but would rather stick to their delusions.
Pointing out that some are not acting/thinking sanely is a effective way to get them pissed enough to try to explain their side of things - when they can't they either take a look at what's going on in their heads or they flail about and go nuts - i consider my "blunt tool" approach to them to be free therapy.
Explain why the comment, "Because, at this juncture, not doing so is stupid." would upset or turn off those who aren't already a bit off-kilter in their thinking. If you can give a rational explanation of why it's not stupid/unproductive to withhold support for Trump, at this point in the Primary, I will apologize to you and every one I may have offended. Remember - I said "rational".