CA-Gov, CA-Sen: County Baselines – Swing State Project

Here is my attempt at estimating the county baselines to see the absolute minimum we can pull in the counties to be able to break 50% statewide in California. Based on trends that I’ve pointed out many times over, close races in California are likely to get rarer and rarer, so I decided that now would be my best chance at showing what a close race in California could look like. Third parties usually pull between 3 and 5% of the vote, so I gave 4% to the third parties.

County	2008 # voters	% of 2008 vote	2008% Pres.	Needed to reach 50%
State	13,743,177	100.0%	61/37	50/46
Los Angeles	3,368,057	24.5%	69/29	58/38
San Diego	1,245,947	9.1%	54/44	43/53
Orange	1,167,657	8.5%	50/48	57/39
Santa Clara	678,033	4.9%	69/29	58/38
Riverside	657,005	4.8%	50/48	39/57
Alameda	628,545	4.6%	79/19	68/28
San Bernardino	616,320	4.5%	52/46	41/55
Sacramento	546,660	4.0%	58/39	47/48
Contra Costa	456,876	3.3%	68/30	57/39
San Francisco	388,112	2.8%	84/14	73/23
Ventura	343,690	2.5%	55/43	44/52
San Mateo	307,350	2.2%	73/25	62/34
Fresno	275,554	2.0%	50/48	39/57
Kern	235,854	1.7%	40/58	29/67
Sonoma	231,817	1.7%	74/24	63/33
San Joaquin	212,214	1.5%	54/44	43/53
Santa Barbara	176,562	1.3%	60/37	49/46
Placer	175,215	1.3%	43/54	32/63
Stanislaus	162,941	1.2%	50/48	39/57
Solano	162,638	1.2%	63/35	52/44
Marin	141,321	1.0%	78/20	67/29
Monterey	131,381	1.0%	68/30	57/39
Santa Cruz	128,555	0.9%	77/20	66/29
Tulare	106,551	0.8%	41/57	30/66
Butte	99,392	0.7%	50/47	39/56
El Dorado	93,890	0.7%	44/54	33/63
Shasta	81,378	0.6%	36/62	25/71
Yolo	80,674	0.6%	67/31	56/40
San Luis Obispo	68,424	0.5%	51/46	40/55
Merced	64,688	0.5%	53/45	42/54
Humboldt	64,358	0.5%	62/34	51/43
Napa	60,366	0.4%	65/33	54/42
Nevada	56,177	0.4%	51/46	40/55
Madera	43,032	0.3%	42/56	31/65
Mendocino	40,580	0.3%	69/27	58/36
Imperial	39,823	0.3%	62/36	51/45
Kings	35,775	0.3%	42/56	31/65
Sutter	33,337	0.2%	41/57	30/66
Tuolumne	27,499	0.2%	42/55	31/64
Lake	25,863	0.2%	58/39	47/48
Tehama	24,803	0.2%	36/60	25/69
Calaveras	23,588	0.2%	42/55	31/64
Siskiyou	21,723	0.2%	43/53	32/62
Yuba	21,681	0.2%	41/56	30/65
San Benito	19,982	0.1%	60/38	49/47
Amador	19,006	0.1%	41/56	30/65
Lassen	11,510	0.1%	31/65	20/74
Plumas	11,169	0.1%	43/55	32/64
Glenn	10,053	0.1%	38/60	27/69
Mariposa	9,756	0.1%	42/55	31/64
Del Norte	9,684	0.1%	45/52	34/61
Inyo	8,625	0.1%	44/53	33/62
Colusa	6,532	0.0%	40/58	29/67
Trinity	6,482	0.0%	50/46	39/55
Mono	5,621	0.0%	56/42	45/51
Modoc	4,505	0.0%	30/67	19/76
Sierra	2,012	0.0%	37/58	26/67
Alpine	697	0.0%	61/36	50/45

Here’s a visual aid, comparing the expected results in a close race in California with the 2008 results:

Hypothetical close race

2008

6 thoughts on “CA-Gov, CA-Sen: County Baselines”

This depends on a uniform swing, which while not unreasonable as an approximation, makes me wonder how we can do better. For instance, a heavily McCain county has fewer Democratic voters to swing, and so would probably have a smaller swing in a 50/50 election. This is most obvious in a hypothetical boundary situation: if there was a 95/5 McCain county in California, the baseline would be negative votes for the Democrat, a clear impossibility. It can similarly be reasoned that a close-to-boundary county would not also have a uniform swing: a 88/12 McCain county is not going to be as likely to vote 99% Republican as a 50/50 McCain district is to vote 61%.

the pale red counties blue, it looks like the 2004 election results

here’s one recent example. And another (this time pretty close to your map).

Comments are closed.