The 48th Assembly District falls entirely within the boundaries of Los Angeles County. Blanca Rubio (D) is the incumbent in this race. Rubio first won a close primary race in 2016 and has held the seat ever since.
This district shows the following party registration for the three largest political groups (the source is http://www.l2political.com):
I have analyzed races with a far worse registration and those seats drew challengers from the right and/or left. Rubio shockingly ran unopposed in 2018 and again runs unopposed in 2020.