The 31st Congressional District falls entirely within the boundaries of San Bernardino County. Pete Aguilar (D) is the incumbent and has held the seat since 2014.

This district shows the following party registration for the three largest political groups (the source is http://www.l2political.com):

Republican- 26.9%
Democrat- 42.8%
NPP- 23.9%

Despite this district showing a fairly sizeable number of Democrats as compared to Republicans, Republican Gary Miller held this seat less than a decade ago. Here are the 2018 primary results:

Pete Aguilar (D)- 45.9%
Kaisar Ahmed (D)- 9.0%
Sean Flynn (R)- 45.1%

If you calculate the totals from this election, you will see that 90,067 ballots were cast. 54.9% of ballots were cast for a Democrat and 45.1% of ballots were cast for a Republican.

We saw a much stronger showing from Aguilar in the 2020 primary. This could be due to the election being a competitive Democratic Presidential race and taking place on Super Tuesday. Here are the results from the March 3 2020 election:

Pete Aguilar (D)- 61.8%
Agnes Gibboney (R)- 38.2%

For this election, we saw 127,996 voters turnout and cast a ballot in this race. Because only two candidates ran, this was basically a preview of the November election.

Per the jungle primary rule in California that require a top two election run-off (regardless of how many candidates run), we will now see a November faceoff between Pete Aguilar (D) and Agnes Gibboney (R). Aguilar is the incumbent member of the US House of Representatives. Gibboney as an immigrant from Hungary who does not currently hold elected office.

Based on comparing the 2018 June vs. November results to the 2020 March results, I see a clear trend. I predict that Pete Aguilar is going to win re-election.