Not very political myself and identify as an independent voter, which is why I'm not a fan of either of them. You'll get drawbacks for both parties and the reality is that Democrats will focus efforts on helping illegal immigrants while Republicans will focus efforts on deporting illegals, which means either way that the focus is on illegal immigrants both for and against and legal immigrants are on the backburner. My brother-in-law was a student from France who had been with my sister while they were in university and graduate school together for about 10 years. When Trump got elected they were filing the paperwork, and there were several changes that negatively affected their application. The new adjustment of status required additional documentation that required more financial documents (public charge) to demonstrate that the beneficiary wouldn't be a public charge. Funding was also removed from USCIS which slowed down processing as well, essentially handicapping USCIS. Yes, my brother-in-law did end up getting his green card but it was delayed by half a year compared to expected timelines from before from new requirements, underfunded/understaffed USCIS, etc.
Basically, long wait times for Trump administration, long wait times for Biden administration. We're not a priority. Essentially the silent killer is always reducing legal immigration levels which is incredibly frustrating.
TL;DR: Both parties suck in concerns to legal immigration for different reasons.