You say it is a vote on principles.
I say it is a vote based upon broken promises.
Elderly Vets Could Face Benefits Cut Under Trump Budget
That is but one example. Medicare, Medicaid, many elderly programs will be affected.
Trump said the below in an interview.
Link However, the link that used to land to a page on the trump site is no longer available.
How GOP Tax Plan Would Ruin Retirees, Underinsured
Unjust GOP budget and tax plan cuts the safety net for seniors
Are Republicans paying for tax cuts with reductions in Medicare, Medicaid?
Tax Bill Provision Would Clobber Seniors
I could get behind your premise that these are principled people who are making sacrifices for the greater good had they actually gone in and voted for Trump because he said something like "Medicaid and Medicare are unsustainable, we must cut those programs and give tax breaks to the corporations." But that isn't what happened. Not at all, and don't try and reframe their votes based upon some heightened sense of self sacrifice. They went into the election believing that they would get to keep all the money they were currently getting.