Sources consulted include Party endorsements and newspaper endorsements:
Also the candidate statements in the voter guide, and candidate websites, and I used VotersEdge a bit to look at fundraising info.
Governor: Newsom. There are other candidates I like more in policy terms -- I might rank Chiang and/or Eastin higher on a preference ballot. But Newsom has political skills that I think people often under-value (his slickness resembles Bill Clinton, in both the bad ways and the good). And the truth is that realistically, it's basically Newsom out front, with Cox and Villaraigosa tied for second. I could make an argument for voting Cox in order to knock Villaraigosa out and make sure Newsom wins in the fall; or I could make an argument for voting Villaraigosa because having two Dems in the fall will depress Republican turnout and help in down-ballot races. Or I can make the argument that trying to give Newsom the maximum margin of victory positions him to have a cruise to victory where he can make his campaign events "rally with Newsom for local candidate X"... Just voting my honest preference among the three seems easiest.
LtGov: Bleich. I find the endorsements in the Chronicle and Mercury persuasive. McLaughlin seems great and I might vote for her on a preference ballot. Koulanakis seems fine as well and I imagine I'll see her name again.
SecState: Padilla. There doesn't seem to be any other serious candidate in the race.
Controller: Yee. Ditto.
Treasurer: Viswanathan. Read the Merc on this.
AttyGen: Dave Jones. For a variety of reasons, but the death penalty is the decisive one. Jones opposes it. Becerra not only supports it, he's tried to use it as a cudgel in the race, accusing Jones of being "unwilling to enforce the law." (See the SF Bay Guardian endorsement.) Yeah, you can get lost, Xavier, and take that unequally-enforced, fundamentally-barbaric law with you. A prosecutor has the discretion to not seek the death penalty; that's within his powers, it's not a failure to enforce anything.
InsCom: Mahmood. I can't bring myself to vote for Poizner after his toxic 2010 campaign, and Mahmood seems like the better choice between the two Dems. Neither is tremendously experienced on insurance specifically; Mahmood's positions on the issues seem progressive without being unreasonable. (Lara has sponsored a single-payer bill with no pay-fors. Mahmood favors single payer, but also favors incremental expansions of the exchange market, mental health parity, etc.)
BoE: Malia Cohen, because she seems marginally better than Galgiani, but the office should be abolished. (Can we elect Lizard People?)
Sen: De Leon. For the reasons the SF Bay Guardian cites.
Rep: Speier. Only Dem, incumbent, she's fine.
Asm: Mullin. Only Dem, incumbent, he's fine.
Judge: Buchwald. I don't think these races should exist at all, and Buchwald doesn't seem like he's done anything to deserve being booted. I disagree with the challenger's premise that there should be a challenger in the race just for the sake of having it contested.
State Super: Thurmond. Mostly on the basis of the LA Times and SacBee endorsements. The Merc's endorsement of Tuck criticizes Thurmond for "undermining" pension reforms, but when I read the article they link to, it really sounds to me like he's engaged in pretty garden-variety reasonable politicking, looking for a compromise bill that would satisfy some valid complaints from CTA. (There are also some fair criticisms that the original bill is better and his compromise would backfire, with districts down-rating more teachers.) Also, Tuck is aligned with Villaraigosa; if Newsom wins there may be conflict between the Superintendent's office and the Governor's.
County Super: Waddell. Magee and Waddell both generally seem good. The local papers seem to think Waddell's Zap the Gap program hasn't done enough, but then in another article in the SM Daily Journal, they report what sounds like substantial progress on an intractable problem:
Oceana High School was held up in the report as a model for improving graduation trends, as the school increased its rate by 4.6 percent between the 2013-14 and 2015-16 school years. The school’s Hispanic/Latino and socioeconomically disadvantaged graduation rates jumped by 7.4 and 11 points respectively over the same time period.
The school was particularly successful in addressing the achievement gap, as its 93.8 percent graduation rate for white students matched its Latino/Hispanic population.
Such an accomplishment is notable in a county where 16 percent of Latino/Hispanic and Pacific Islander students did not graduate last year, according to the county report which also claims 23 percent of black students failed to graduate.
The only substantive difference reported between the two is that Waddell is more skeptical of charters, which the PA Daily Post presents as a negative; I disagree.
Clerk-Recorder: Church. Mooney's campaign issue is the standard GOP in-person voter fraud lie.
Sheriff: Melville. His experience comes from smaller towns, but nobody seems to think he did a bad job. And Bolanos has a super-shady incident in his past in which he appears to have been covering for his boss, in blue wall of silence style, when they were both detained at an illegal brothel. ( https://www.eastbaytimes.com/2008/04/18/lawmakers-demand-probe-of-sheriffs-las-vegas-brothel-visit/ ) Honestly if they'd gone to something legal past the county line, I wouldn't consider it relevant, but this is ugly; the fact that both Bolanos, and the law enforcement officers in Vegas, gave Munks impunity to violate the law is even uglier.
The papers and the party all seem to be in universal agreement about the propositions this year. So that's nice. (Pete Stahl over at PeteRates.com also mostly agrees, though he ends up dissenting on Prop 72 for "heightening the contradictions" type reasons related to Prop 13; I'm not buying it.)
Prop 68: Yes. Bond measure from the legislature, for stuff I approve of. I don't think these should even require voter approval.
Prop 69: Yes. I'm not crazy about limiting the use of funds, but in this case the opponents are angling to use the fact that the funds aren't beyond the legislature's reach, in a campaign to entirely repeal the gas tax and vehicle fee that generate the funds in the first place. This appears to be an OK compromise under the circumstances.
Prop 70: No. Basically gives the GOP minority a blocking vote on using cap-and-trade revenues for anything.
Prop 71: Yes. Puts in place an appropriate delay to let votes actually get counted, before implementing propositions as law.
Prop 72: Yes. Adds rainwater capture systems to an existing program that excludes various environmental upgrades from being added to your property tax basis.
Measure 3: Yes. Not crazy about the bridge toll hikes, but it funds a lot of worthy projects, and it's not clear how long we'll have to wait to find funding for them if it doesn't pass.