The 42nd Congressional District falls entirely within the boundaries of Riverside County. Ken Calvert (D) is the incumbent and has held the seat since 2012 (after he was re-districted from the 44th). Gary Miller used to hold this seat before being districted out.
This district shows the following party registration for the three largest political groups (the source is http://www.l2political.com):
Calvert has been a long time figure in Congress and he has always shown strong primary numbers when running. Here are the 2018 primary results:
Norman Quintero (D)- 8.2%
Julia Peacock (D)- 26.1%
Ken Calvert (R)- 60.8%
Matt Woody (NPP)- 2.3%
110,066 ballots were cast in this race. That is a strong turnout number when compared to other districts in 2018. With Calvert clearing 60%, it was clear that he would win in November. It is highly unlikely for any candidate to get over 60% of the vote in a primary and not win in November.
In spite of the much higher Democrat turnout in March 2020, Calvert still had a strong showing. Here are the results from the March 3 2020 election:
Regina Marston (D)- 18.2%
William “Liam” O’Mara (D)- 22.6%
Ken Calvert (R)- 59.2%
153,826 ballots were cast in this race. Calvert did not clear 60% in the primary; however, he is close enough o be pretty safe in November.
We will now see a November matchup between William “Liam” O’Mara (D) and Ken Calvert (R). Calvert is the incumbent member of the US House of Representatives. O’Mara has strong family ties to unions and is very supportive of labor.
The numbers regardless of Trump popularity show a Republican is in the strongest position to win this seat. I predict that Ken Calvert is going to win re-election.