You sound like you could be a terrific candidate for this undergrad fellowship program at Claremont McKenna: About 1 — Keck Center for International and Strategic Studies (Not something you can apply to until you’re there, but just to give you an idea of the kind of opportunities that are available.) IR and poli sci are very strong at the Claremont Colleges, and the consortium-wide campus newspaper has launched some impressive journalism careers. Recent grads from just the past couple of years are working at the NYT, WSJ, and SF Chronicle. As MWolf pointed out, the 5C’s have a grad school - not that undergraduate-only should be a deal-breaker, but this might make the concept more palatable to your family. CMC, Scripps, and Pomona are all Questbridge partners. If applying outside of Questbridge, CMC heavily favors Early Decision applicants.
Make a spreadsheet of all the schools you’re looking at; run the NPC’s for all, and note your projected net cost for each. California is a pretty good state in terms of providing adequate aid for lower-income students at its public universities, but you may still find that your prospects for minimizing debt are better at private institutions. (Questbridge Match is the best case scenario, but odds of Matching are fairly long so that’s not to be counted upon.)
Most OOS publics won’t be practical financially, but a few do meet need: UVA, UNC Chapel Hill, and for low-income students, UMichigan. Run the NPC’s for these too.
Agree that Northwestern Medill is the proverbial brass ring for your interests - all students choose an academic concentration outside of journalism, which can be poli sci. UPenn is another one to look at - the undergrad Communication major is in Arts & Sciences, but administered and taught by Annenberg faculty - an optional concentration in Politics and Policy is offered within the Communication major.
Northeastern U could also be worth a look - you can do a combined degree in Journalism and Poli Sci there, with co-op placements that can really help to build a resume. Journalism and Political Science, BA < Northeastern University Again, run the NPC - they can be generous with some financial profiles and stingy with others.
Good luck!