If conservatives had to name just one Senate race they’d most want to win, the election in California would have to come at the top of the list.  Barbara Boxer remains in the lead, albeit within the margin of error, according to the latest Rasmussen poll — and still below the 50% line incumbents need to cross.  The race has changed little over the last few weeks:

Incumbent Democrat Barbara Boxer continues to hold the slightest of leads over Republican challenger Carly Fiorina in California’s U.S. Senate race.

The latest Rasmussen Reports telephone survey of Likely Voters in California shows Boxer with 49% support and Fiorina with 46%. Two percent (2%) prefer another candidate in the race, and three percent (3%) are undecided. …

Just over a week ago, Boxer, who is seeking a fourth six-year term, posted a similar 49% to 45% lead over Fiorina, a former CEO of Hewlett-Packard. Boxer has held a small lead in every survey but one since February with 42% to 49% of the vote. Fiorina, in those same surveys, has earned 38% to 47% support.

Rasmussen calls it a toss-up, but Fiorina needs to start showing some momentum if she wants to catch the incumbent.  Barack Obama won California by a 24-point margin, 61/37, and still has a 57/42 job approval rating among likely voters.  Boxer still has a net positive favorability rating, 50/46, which matches up with Fiorina’s 49/45 almost exactly.

The issues don’t provide a good indicator of how late-deciding voters will break in either direction.  Repealing Obamacare is narrowly popular, 49/45, but half of all Californians approve of the federal mandate, 50/46.  The only real bright light in the issues questions is on jobs, with only 17% of voters thinking that the job market has improved, compared to 40% who believe it has worsened and 41% who think it hasn’t changed at all.  If Fiorina can tie Boxer to the jobs issue, she may squeeze out a victory in this race.

Fiorina’s statement in response to this poll drives right at that issue:

“Today’s poll confirms that, after spending more than $10 million on baseless, political attacks against Carly, Barbara Boxer still can’t convince voters she’s deserving of another six-year term in Washington. With a demoralized base, Californians suffering under the weight of 12.4 percent unemployment and the broken promise about the ‘help and hope’ Boxer said would come as a result of the economic stimulus plan, it’s no surprise she is now resorting to scare tactics in her continued desperation to save the one job she cares about: her own.

“Californians are entirely focused on the economy – and the fact that Barbara Boxer hasn’t been able to deliver results for the people of this state and is now trying to distract voters from that dismal record only underscores just how out of touch she has become during her 28 years in Washington. And as our campaign continues to draw a sharp contrast between Boxer’s record of failure with Carly’s proven record of leadership in creating jobs and her fresh perspective on economic growth, we expect Boxer’s support to falter and Carly’s to continue growing.”

That support should have been faltering a few weeks ago.  Thus far, while Boxer doesn’t seem secure, she hasn’t lost much ground yet, either.  Fiorina needs to step up the campaign another level to push her line of attack.