Meg Whitman is running a full-court press to force Steve Poizner out of the Republican race for governor, which shows just how concerned she is about an upcoming series of Democratic attack ads.

On Wednesday, for example, her campaign announced that Assemblyman Sam Blakeslee of San Luis Obispo, the former minority leader, had dropped his endorsement of Poizner and was moving into the Whitman camp.

A trio of GOP legislators, state Sen. Mark Wyland of Escondido, Assemblyman Jim Nielsen of Yuba City and Assemblywoman Connie Conway of Tulare, also magically picked Wednesday as the day to urge Poizner to “do the right thing, step aside and join us in supporting Meg.”

Whitman even took what’s been a rare move for her by actually talking, however briefly, to a few California reporters this week.

“Democrats are worried about my candidacy,” she told KCBS radio in San Francisco.

It’s not that the two radio spots released so far are anything special, focusing as they do on the millions of her own money the former eBay CEO is expected to spend on her campaign (although the slogan, “Because the California Governor’s Office Should Never Have a ‘Buy It Now’ Button” has a ring to it).

It’s the very fact that there now are attack ads out there at all that’s got Team Whitman in overdrive to push Poizner over the side and clear the primary field.

If Whitman and her supporters don’t get Poizner out now, it might never happen because once those new ads start showing up on radio stations across the state, Whitman’s air of invincible inevitability is going to take a beating.

Again, that has little to do with the specific content of the new spots and everything to do with the fact that there will be something out there to counter nearly five months and more than $3.5 million worth of feel-good advertising by Whitman.

Since September, Whitman has had the airwaves to herself, giving Californians her own take on the state’s problems and her own particular view of what needs to be done. She’s portrayed herself as a hard-nosed businesswoman who’s the answer to the state’s woes and there’s been no one out there to say anything different.

Not surprisingly, that advertising has helped drive both her visibility and her poll numbers steadily higher, to the point where a new Rasmussen poll has her in a dead heat, 43 percent to 43 percent, with Attorney General Jerry Brown, the officially unannounced Democratic candidate.

That same poll also showed her running just two percentage points behind Sen. Dianne Feinstein, California’s most popular politician, in a hypothetical November match-up for governor.

But that’s going to change and the pros running Whitman’s campaign know it. Negative advertising works, at least for awhile, so if Level the Playing Field 2010, the none-too-independent expenditure committee targeting Whitman, can follow through on its threat to bury her under $20 million of mud, those poll numbers will take a hit.

It’s no great shock that the anti-Whitman radio spots are running on conservative-friendly talk radio shows across the state, targeting the folks most likely to vote in the June GOP primary. Although the veteran Democratic consultants behind the ads piously deny they have any interest in helping Poizner, the prospect of a hard-fought – and expensive – Republican primary battle is good news for Brown, regardless of who finishes on top.

That means the next move is up to Poizner. He had $17.7 million in the bank on Jan. 1, but still hasn’t shown an inclination to spend much of it.

Poizner, who’s far behind in the polls, has said time and again that he’s in the governor’s race to stay, but in politics the shelf life of those declarations can be brief (see: Newsom, Gavin).

In an effort to calm nervous Poizner supporters, former state Sen. Jim Brulte, Poizner’s campaign chair, sent a letter Wednesday, asking why “if the Whitman team is so confident of winning the primary, why all the effort to get Steve’s supporters to switch?”

Still, even Poizner supporters may see that high-priced Democratic attack on Whitman as evidence that she’s the candidate Brown fears most. Poizner now has to show them that’s not so.

Both candidates are scheduled to square off March 15 in a long-awaited debate in front of an Orange County Republican group. It’s unlikely that Poizner would even think about ending his campaign before then, since he’s hoping the debate will be the momentum changer that will finally swing the campaign his way.

But hope will only take Poizner so far. With the Democrats piling on Whitman, he now has a chance to make some serious headway by getting his own story out to GOP voters – and yes, that means spending plenty of money right now. If Poizner can’t take advantage of this one-time-only opportunity to tighten the race, it really won’t matter much whether he stays or he goes.

John Wildermuth is a longtime writer on California politics.