It’s not a shock to learn that voters in dark-blue California are deeply unhappy with President Trump, but a new poll suggests the growing antipathy could be terrible news for a number of the state’s GOP congressional incumbents.

While two-thirds of California’s registered voters in a poll by the Berkeley Institute of Governmental Studies disapprove of the job Trump is doing, 59 percent of the voters in seven competitive GOP congressional districts feel exactly the same way.

What’s even more worrisome for GOP leaders is that the Democratic candidates in those districts are trying to turn the elections into a referendum on Trump, and the poll numbers suggest that’s a contest the president — and his party — easily could lose.

“I don’t think those (congressional) candidates are going to want Trump campaigning for them,” said Mark DiCamillo, the poll’s director.

What’s striking about the poll is the sheer level of animosity shown by Democrats, he added.

While 67 percent of the state’s voters disapprove of Trump’s job performance, “59 percent disapprove strongly, and that’s off the charts,” DiCamillo said.

But the poll also shows that beleaguered and outnumbered California Republicans aren’t ready to wave the white flag. While 91 percent of Democrats disapprove of the job the president is doing, along with 69 percent of no-party-preference voters, 80 percent of Republicans still back Trump.

Two-thirds of Republicans think the government investigation into Russia’s possible involvement in the 2016 presidential race is not important; 65 percent are not confident the investigation by Special Counsel Robert Mueller will be conducted fairly; and 75 percent believe the investigation should be scaled back or shut down, compared with 88 percent of Democrats who believe the investigation should be pursued, wherever it leads.

“Republicans are standing by their man,” DiCamillo said.

That partisan chasm is on full display in the poll’s survey of 12 policy areas, ranging from the economy and immigration to race relations and the environment. While Democrats disapproved of Trump’s performance in every area, GOP voters backed the president in each one.

The poll is based on an online survey of 4,038 registered California voters and was taken April 16-22. The margin of error is plus or minus three percentage points.

— John Wildermuth

AG race gets heated: The race for attorney general is getting nastier, with Democrat Dave Jones going on the attack against retired El Dorado Superior Court Judge Steven Bailey , who with Los Angeles attorney Eric Early is one of the two Republican candidates in the contest.

On Monday, Jones sent out a news release calling Bailey the leading GOP candidate in the race and none-too-subtly pointing out that “this candidate is under investigation for 11 counts of judicial misconduct.”

Jones, the state insurance commissioner, also made sure to point out that Bailey is supported by “numerous conservative organizations,” including the Pro-Life Council and Gun Owners of California.

“California voters deserve to know the facts about Steven Bailey — the leading candidate of a major party — BEFORE the June election,” the release states.

Bailey’s team sees it differently, of course.

“We have said all along that this inquiry is a political attack, and the insurance commissioner just proved it,” Corey Uhden, a campaign spokesman, said in a statement. “The Commission on Judicial Performance admits their inquiry is not a finding of judicial misconduct. It is nothing more than an attempt by liberal appointees of Gov. (Jerry) Brown to disparage the Republican candidate for attorney general.”

Jones’ attack normally would be like using a sledgehammer on a gnat. He’s a former Sacramento councilman, Assembly member and two-term state insurance commissioner who has $3.4 million in his campaign account.

By contrast, the little-known Bailey has never been elected to anything but the Superior Count in his tiny mountain county and has $13,664 in the bank for his statewide campaign.

But California’s top-two primary is the reason Jones is spending time and probably money whacking on Bailey instead turning his fire on the likely front-runner, appointed incumbent Xavier Becerra, a fellow Democrat.

Since the two candidates with the most votes in the June 5 primary, regardless of party, move on to the November election, a second-place finish is just fine for Jones. But while Bailey doesn’t have enough cash to even run more than a few days of radio advertising in South Lake Tahoe, he does have an “R” after his name on the ballot.

Democrats far outnumber Republicans in California, but if GOP voters unite behind a single Republican and Democrats split their votes between two well-known and well-financed candidates, it could put that Republican in and leave a Democrat like Jones out.

Expect Jones to spend what it takes to try and make sure that doesn’t happen.

— John Wildermuth

John Wildermuth is a San Francisco Chronicle staff writer. Email: jwildermuth@sfchronicle.com Twitter: @jfwildermuth