The 27th Congressional District falls within the boundaries of Los Angeles County and San Bernardino County. Judy Chu (D) is the incumbent and has held the seat since 2012.
This district shows the following party registration for the three largest political groups (the source is http://www.l2political.com):
We had a unique situation in 2018 with no Republicans running. Judy Chu was facing a Democrat as her opponent. As outlined below, Chu easily won the Primary and also coasted in November:
Bryan Witt (D)- 16.5%
Judy Chu (D)- 83.5%
If you calculate the totals from this election, you will see that 104,118 ballots were cast. Obviously all ballots were cast for a Democrat.
2020 had a much different field running in the Primary. Two Republicans and an NPP candidate all ran in the jungle primary. I never like to see multiple candidates running in a primary in a seat that is hopeless (from either party). Here are the results from the March 3 2020 election:
Judy Chu (D)- 70.4%
Beatrice Cardenas (R)- 11.9%
Johnny Nalbandian (R)- 13.8%
Christian Daly (NPP)- 3.9%
For this election, we saw 152,927 voters turnout and cast a ballot in this race. 70.4% of voters cast a ballot for a Democrat and 25.7% of voters cast a ballot for a Republican. If you look back at the party registration for CD 27, you wonder why an NPP candidate didn’t do better. Considering NPP voters have over an 8% advantage over Republicans, it is interesting to see an NPP candidate so far down the list.
Per the jungle primary rule in California, we will now see a November faceoff between Judy Chu (D) and Johnny Nalbandian (R). Chu is the incumbent member of the US House of Representatives. Nalbandian is a businessman and member of the Armenian Community.
The party registration in this race make this one an easy call. I predict that Judy Chu is going to win re-election.