The 55th Assembly District falls within the boundaries of Los Angeles County, San Bernardino County, and Orange County. Phillip Chen (R) is the incumbent in this race. Chen initially lost to Ling Ling Chang in the 2014 election; however, after Chang chose to run for Senate in 2016, Chen ended up winning the open seat.
This district shows the following party registration for the three largest political groups (the source is http://www.l2political.com):
In spite of the seat lacking an incumbent in 2018, Chen dominated the field. Here are the result for the June 2018 race:
Gregg Fritchle (D)- 22.6%
Melissa Fazli (D)- 15.5%
Phillip Chen (R)- 47.2%
James Gerbus (R)- 10.8%
Scott Lebda (R)- 3.9%
Based on registration, you would expect this seat to be competitive. Republicans do very well on a consistent basis in this district. My point was proven in the 2018 November results. Chen won by a margin of 54.9% to 45.1%.
In 2020 the seat looks like it could be much more competitive. Here are the March 2020 results:
Andrew Rodriguez (D)- 43.8%
Phillip Chen (R)- 56.2%
We can expect a closer race in the rematch between Phillip Chen (R) and Andrew Rodriguez (D). Chen is the elected incumbent and Rodriguez is the Mayor of Walnut.
Rodriguez is an extremely viable opponent and registration is tight in this race. Chen has experience and name ID on his side, along with the fact that it appears NPP voters lean conservative. I predict that Phillip Chen will win a very close race in November.