Sen. Barack Obama has surged into a virtual tie with Sen. Hillary Clinton in California’s Democratic presidential primary, according to the latest Field Poll.  Obama’s campaign credits — get ready — organization:

Obama’s California campaign team said the latest polls reflect a hard-charging effort to track down potential voters in every precinct – undeterred by polls that showed the Illinois senator behind by double digits here for most of the race.

“If we hadn’t laid the groundwork for the last year, we couldn’t be delivering now,” Debbie Mesloh, spokeswoman for the Obama campaign, said Saturday.

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“We always knew it would tighten,” he said. “But we’re incredibly confident in the organization we have to get out the vote.”

If you missed the Saturday evening post on the Democratic ground game in California, you clearly had better things to do with your time than I did.  But you can read it now.  With 18% of Democratic voters in Cali still undecided, there is still plenty of volatility.  Indeed, depending on the poll’s turnout model – how many blacks, Hispanics, young folks, independents, etc. — the race may not be quite as tight as two points.  But I would think Clinton has to be worried about the residual John Edwards voters riding their silky ponies into Camp Obama.

On the GOP side, the Field poll has Sen. John McCain with a 32% to 24% lead among likely voters over Mitt Romney.  That’s up 10% for McCain since mid-January, but also pretty good for Romney, considering that McCain leads Romney by 24% nationally in the new WaPo/ABCNews poll.  Eight points in California is not too far removed from the four point margin Rasmussen reported last week before Rudy Giuliani bowed out of the race.

Rasmussen also had good news for Romney from Missouri, where the latest numbers had John McCain narrowly on top at 32% followed by Mike Huckabee at 29% and Mitt Romney at 28% in the bellwether state.  Romney had been down nine points in the “Show Me” state before McCain won the Florida primary.  Romney is down by eight points in Illinois.  Both California and Illinois award delegates by Congressional district (albeit with a bonus for the statewide winner), which may give Romney some opportunities in those states, while Missouri remains a winner-take-all state that seems up for grabs.

The most recent polls from Tennessee are widely divergent on Romney — Insider Advantage has him at 18%, while a Rasmussen poll from the same day has him at 29%.  It’s probably closer to 18%, but Huckabee is strong there and there looks to be about 15% undecided (Fredheads still in mourning).  Tennessee awards delegates by proportional representation, so it is likely that the major candidates will all get some of those 55 delegates.

Overall, Romney still has a rocky road to travel on Tuesday.  But even after Super-Duper Tuesday, 45% of the delegates will remain to be allocated.  The WaPo’s Dan Balz writes:

McCain’s big lead in this new national poll matches a wave of increasing support seen in state polls, which, coupled with the GOP’s winner-take-all rules, gives him the opportunity to effectively wrap up the nomination with a strong showing Tuesday.

Balz is demonstrating a lack of familiarity with the GOP’s delegate rules in the various states, likely combined with some wishful thinking on his part.  Johnny Mac is poised for a Fat Tuesday, but the fat lady probably won’t be performing.

Update:  In the comments, Brainster notes that Rasmussen had Romney up in Florida and suggests the firm’s polling may be skewed with respect to Missouri (the Tennessee poll was the one that looked off to me).  The spanking new Mason-Dixon polls for several SDT states has McCain up by nine points in California, six points in Georgia, 13% in Missouri and 15% in New Jersey.  I would note (as I did last night) that Rasmussen has generally had the Democratic race tighter than other firms as well.  There are a number of factors which can account for this.  Different firms can have different screens for likely voters.  Rasmussen uses automated response technology; other firms may use in-person interviews.  And Rasmussen seems to push leaners to give an answer more than other firms.  In the Missouri polling, Rasmussen has only three percent undcided; Mason-Dixon has 11% undecided.  Also, the Mason-Dixon polls have a five percent margin of error, which means their numbers for Missouri signal anything from a McCain blowout to the tight race Rasmussen suggests.  I have previously written that events like primaries help demonstrate the uncertainties in polling that usually remain hidden when there are not simultaneous competing polls to compare.  This is another example of why my election-related posts usually try to downplay the horse race.

Updatex2:  FWIW, the Zogby tracking poll has McCain way ahead in Missouri, but in a virtual tie with Romney in California.