This is one of the districts that I am most familiar with because I am a resident of the 45th and also had a client unsuccessfully run for the seat in the Primary.
The 45th Congressional District falls entirely within the boundaries of Orange County. Katie Porter (D) is the incumbent after she defeated Mimi Walters in the November 2018 election.
This district shows the following party registration for the three largest political groups (the source is http://www.l2political.com):
Let’s take a look at the 2018 results for the June and November election:
Dave Min (D)- 17.8%
Kia Hamadanchy (D)- 1.9%
Katie Porter (D)- 20.3%
Brian Forde (D)- 6.0%
Mimi Walters (R)- 51.7%
John Graham (NPP)- 2.3%
Here is a chart that shows the vote total and percentage of the vote by candidate for the 2018 Primary:
Democrat Candidates– 77,376 votes & 46.0% of the vote.
Republican Candidates– 86,764 votes & 51.7% of the vote.
Independent/NPP Candidates– 3,817 votes & 2.3% of the vote.
Grand Total– 167.957 votes cast.
I have a rule that the vote shifts 5% up for Democrats and down for Republicans from a primary to a general election in Orange County. Let’s assume that the 3rd party/NPP vote split between the Republican and Democrat. This theory would then predict that the Republican candidate should receive 49.0% of the vote in November and the Democrat 51.0% of the vote.
Porter narrowly outperformed my model and won in November by with 52.1% of the vote vs. 47.9% of the vote for Walters. Porter received 158,906 votes and Walters received 146,383 votes.
Here is a breakdown of the actual results for November of 2018 broken down by who won each city:
Porter– East Orange, Irvine, Laguna Woods, Silverado, and Tustin
Walters– Anaheim, East Tustin, Laguna Hills, Lake Forest, Mission Viejo, Orange, Rancho Santa Margarita, Trabuco, Unincorporated OC, and Villa Park
Even though Walters won a majority of regions, Porter won by a large enough margin in just Irvine & Tustin to win.
Here are the results for the 2020 March primary election:
Katie Porter (D)- 50.7%
Rhonda Furin (R)- 1.0%
Christopher Gonzales (R)- 2.4%
Peggy Huang (R)- 11.1%
Greg Raths (R)- 18.0%
Don Sedgwick (R)- 12.8%
Lisa Sparks (R)- 4.0%
As expected with the election being held on Super Tuesday, voter turnout was noticeably higher. We saw a total of 222,158 votes cast. 50.7% of the vote went for Democrats and 49.3% of votes went to a Republican.
These numbers are even worse than the 39th district, using my 5% rule from above. Even if you total all the votes that went to a Republican, the model predicts that Porter will win re-election by a margin of 55.7% of the vote to 44.3%. The margin is close enough to where a strong campaign could pull out a win but it will take an incredible effort to flip this seat.
Due to the crowded field, let’s look at the top three finishers by region in the March 3 2020 race:
Anaheim– 1) Porter 2) Raths 3) Huang
Irvine– 1) Porter 2) Raths 3) Huang
Laguna Hills– 1) Porter 2) Sedgwick 3) Raths
Laguna Woods– 1) Porter 2) Raths 3) Sedgwick
Lake Forest– 1) Porter 2) Raths 3) Sedgwick
Mission Viejo– 1) Porter 2) Raths 3) Sedgwick
Orange– 1) Porter 2) Raths 3) Huang
Rancho Santa Margarita– 1) Porter 2) Raths 3) Sedgwick
Tustin– 1) Porter 2) Raths 3) Huang
Unincorporated OC– 1) Porter 2) Raths 3) Sedgwick
Villa Park– 1) Porter 2) Sedgwick 3) Huang
1) Will Porter be able to run as a moderate again, now that she has a very left-leaning record in Congress?
2) Will organizations consider Greg Raths a viable candidate and invest in his race?
I predict that Katie Porter will win re-election here. Before I get accused of having sour grapes because my client did not make it thorough the primary, I will state that the numbers lead me to believe that none of the Republicans would have been able to win in November.