Why are downtown Austin precincts not very D?

[支持核绿派 (Greens4Nuclear)]

(Breaking my March posting hiatus for the sake of Leipism)

It's not even all of Downtown Austin, it's just 2 precincts surrounding the Austin Convention Center on the west side of I-35 and the north bank of the Colorado River. (I'm guessing the third 70-30ish Biden precinct with very few voters contains the State Capitol). I don't think it's really a racial thing because the similarly White precincts across the Colorado are also >80% Biden like the surrounding precincts on/past the UT Austin campus and the precincts just on the other side of I-35.

Austin proper historically had a racially divide along I-35, with the hillier west side (including downtown) being more overwhelmingly Non-Hispanic White and the flatter east side being more Black and Latino. Both of the places my family lived in the early 2000s were west of I-35 and outside of the 360-71-US 183 loop but still within city limits.