Actually, it seems that for most service members joining the military is one of several potential choices, and they simply weighed it as the best one for a handful of top reasons: Opportunity for career advancement, financial stability, having a family member already in the military, student financial support incentives, and moral / patriotic reasons. It's a popular myth that a large portion service members are there for lack of any practical alternative, in fact very few are. The DoD recruitment budget (Marketing campaign) is over $4 Billion annually last I checked, for the good reason that most recruits have to be convinced.

https://worldmetrics.org/reasons-for-joining-the-military-statistics/#b-7-data-sources
https://journals.sagepub.com/doi/10.1177/0095327X251399177
https://docs.opa.mil/opa.mil-production1/reports/futures_surveys/YP60Fall2024PUBLICRELEASEPropensityUpdate_20250623_Briefing.pdf

It might have been their only chance at an education or they were dirt poor and this was the only career available that didn’t involve dealing drugs.

That's really a myth. Most of the military come from middle and upper middle classes, and those growing up in lower income households are underrepresented compared to the general population.

Unless I'm mistaken, didn't a significant percentage of military personnel vote for Trump?

The facts don’t support your feelings.