Thread by @JMilesColeman

Well guys, tonight on #ElectionTwitter, we're gonna be looking at Orange County. It's California's third most populous county and will be critical for the 2018 midterms.

Why is Orange County so interesting? Well, to start, it was one the relatively few Romney -> Clinton counties. She won it by almost 9%, becoming the first Democrat to carry it since FDR in 1936.

Despite the county flipping to Clinton, a quartet of districts there (or at least partially contained within OC) reelected R incumbents to Congress: #CA39, #CA45, #CA48, and #CA49.

Going numerically, we'll start with #CA39. It's rep'd by Ed Royce (R). Roughly 2/3 of it is the northern part of OC (Fullerton, Yorba Linda, La Habra, etc.). It also takes in parts southeastern Los Angeles and western San Bernardino Counties. Overall, it resembles a goldfish.

Clinton carried #CA39 by 9% (!) - roughly matching Orange County, overall. For some perspective, in 2012, it narrowly voted against Feinstein and Obama. In 2014, none of the statewide Dems were within single-digits of carrying it.

Now, to the precinct maps! Despite Clinton winning #CA39 by 9%, Rep. Royce was reelected by 14%. Not surprisingly, Royce ran ahead of Trump basically everywhere:

One of the most interesting #CA39 stats (maybe for Orange County, overall) is that a PLURALITY of precincts there voted for Clinton but crossed over for Rep. Ed Royce (R):

Next, we look at #CA45 - this is entirely within OC. It's rep'd by Mimi Walters (R), who was first elected in 2014. It takes in cities like Irvine, Kathryn, Tustin, Mission Viejo, and Laguna Hills.

Clinton carried #CA45 by 5.5%, but before that, Obama lost it by 12%, and Feinstein only barely did better. Almost all of the 2014 statewide Democrats lost CA-45 by >20%, even as they all won the state.

Walters was reelected by 17% while Clinton won by 5.5%. Walters did better than Trump in all but one precinct in #CA45.

Like the other Rs in Orange County, Rep. Walters (R) won over a lot of Clinton precincts. In #CA45, there were actually more Clinton/Walters precincts (pink) than Clinton/Dem precincts (blue):

Our next Clinton/GOP seat in Orange County is #CA48. Rep. Dana Rohrabacher (R) was first elected in 1988. This seat hugs the coast. It starts in the Huntington Beach area, picks up cities like Costa Mesa & Newport Beach, and ends up around Laguna Beach.

Of these four Orange County seats, #CA48 was the most narrow Clinton win, going to her by <2%. Obama/Feinstein both lost it by double-digits (10-12%) in 2012. The best Dem there in 2014 was Gov. Brown, who lost it by 15%.

Following the pattern, Rep. Rohrabacher (R) won by 17% in 2016, while Clinton carried his #CA48 by 1.7%. Rohrabacher did better than Trump basically everywhere, especially around Fountain Valley.

In #CA48, Rohrabacher got *a lot* of crossover from Clinton voters. There were almost twice as many HRC/Rohrabacher precincts (pink), 128, than HRC/Dem precincts (blue), 69.

Last, we have #CA49. Rep. Darrell Issa (R) is known for his role as chair of the House Oversight Committee. CA-49 is actually mostly in San Diego County, but about 1/4 of it is OC. Has Camp Pendleton, plus coastal cities like San Clemente Oceanside, Carlsbad & Encinitas.

Clinton won Issa's #CA49 by 7.4%. In 2012, Obama and Feinstein each lost it by 6.6%. In 2014, Gov. Brown lost it 55/45, though Treasurer John Chiang's strength here is notable. He 'only' lost it by 9% (and is now running for #CAGov, himself).

In 2016, Rep. Darrell Issa (R) had the most competitive race, out of the Orange County Republicans. While Clinton carried his #CA49 by 7.4%, he was reelected with 50.3%. He did better than Trump most places, with the big exception of Camp Pendleton, in the middle.

As #CA49 was the most competitive of these four, it's not surprising that it had the least amount of crossover precincts. 50 precincts (pink) went for Clinton & Issa while three (light blue) even voted for Trump & Applegate.