If I don't take AP United States History, will it hurt my chances?

2nd semester senior years do matter if you get senioritis or if you delay enrollment but it's essentially a formality. APUSH helps GPA as UCs use WGPA, not UWGPA. but with your course load, it is not needed but APs in your major area are better than non major related ones. Is it needed absolutely not but would it help you certianly.

I don't think that not taking one course will "hurt" your chances, especially considering that you have other courses (American History Honors, AP world, AP Hu Geo, AP Econ, AP environ, AP Gov) that relate to your major (pol sci)

You definitely don't have to take APUSH to get into an UC. You took a lot of other APs that show you more than capable of taking advanced courses, which is the entire point of taking AP classes in the first place. For your other question, in short, they don't matter as much as other semesters, but colleges do still look at them after you're accepted just to make sure you didn't completely slack off your senior year. Make sure to push through!

For my state, it's a graduation requirement to take some form of US history, so I took APUSH. I'm slightly confused why you chose to take American History Honors instead, but it should be okay. I'm also very confused why you took Government Honors and self-studied for the AP test instead of taking the AP class when it's offered for underclassmen. Are you a current junior? If so, a few things:

1) AP human geography is the default freshman class offered at my school; it's not difficult but also doesn't really offer that much useful credit. idk about UCs though

2) if you have time to take both AP Lit and Lang, maybe just consider dropping one and doing APUSH since they often give credit for the same thing. again, check UC though