Has California’s Sweetheart, Senator Ma’am, suddenly fallen out of favor on the Left Coast?  A new Field Poll suggests that the upcoming Senate election has California voters reassessing their incumbent — and that doesn’t bode well at all for Barbara Boxer.  Even before the campaign gets into high gear, Boxer finds herself underwater in both job approval and favorability:

California voters are giving U.S. Sen. Barbara Boxer some of the lowest approval ratings of her career, as the three-term Democrat is in a statistical dead heat against first-time GOP office-seeker Carly Fiorina, according to a new Field Poll released today.

Boxer leads Fiorina, the former Hewlett-Packard CEO, 47 to 44 percent, according to Field’s survey of 1,390 registered voters, 1,005 of whom were considered likely to vote in November. The poll, conducted June 22-July 5, has a margin of error of 3.2 percentage points among likely voters. For Boxer’s job performance ratings among registered voters, the margin of error is 2.8 percentage points.

Boxer’s slight numerical lead masks potentially serious problems for the senator, starting with how 52 percent of the respondents hold an unfavorable view of her.

That will become a problem, as this chart shows that very few voters have no opinion of Boxer — and therefore she has little opportunity to make up that ground.  For Fiorina, she has plenty of room to make a case for herself as a better choice:

This also shows some risk for Fiorina, and a need to start flooding the zone immediately.  The Republican nominee needs to define herself before Boxer can do it for her.  Fiorina has already shown progress in converting the “no opinion” contingent, but having a majority of voters undecided leaves a big opening for one’s opponent.  Boxer can win if she can make Fiorina look like a worse choice than herself in what can be called the Reid strategy this year.

However, like Harry Reid, that appears to be the only path to victory for Boxer.  Her negatives have increased rapidly over the past year, in both how voters see her personally and how they view her performance.  This will also impact turnout, although having a gubernatorial race on the ticket could help Boxer in that regard — had Democrats nominated a compelling candidate for that office.  Instead, they’re offering a 1970s Leftist retread in Jerry Brown, which will turn out the vote in San Francisco and probably nowhere else in the state.

Fiorina still won’t have an easy time winning in a heavily Democratic state.  But her money and Meg Whitman’s will almost certainly help get a maximum turnout among Republicans while Democrats glumly watch a tsunami roll towards them from the Eastern seaboard on Election Day.