The San Francisco Chronicle’s Carla Marinucci reported recently that Tom Campbell may be dropping out of the governor’s race to run for the US Senate against Sen. Barbara Boxer. If this is true, it could be a blockbuster event in campaign 2010.

Campbell’s thinking seems driven by two realities; he doesn’t have enough money to compete in the GOP gubernatorial primary, and the nomination may be worthless anyway as some polling shows Attorney General Jerry Brown poised to win in a landslide.

But if he shifts to the Senate contest, he will have one huge impact – and it is not his nomination, but that of Assemblyman Chuck Devore. A Campbell candidacy probably finishes off the GOP establishment favorite, businesswoman Carly Fiorina. Her base is among the Silicon Valley GOP types, as is Campbell’s, and with the declining Republican Party in California, there is simply not room for two Silicon Valley Republicans.

Devore is on the right wing fringe of California politics, and his soulmates have regularly been trounced when running statewide. Former Sen. Dick Mountjoy received only 35 percent against Sen. Dianne Feinstein in 2006, but GOP registration has noticeably declined since 2006. It is now at an historical low at under 31 percent, and it is very questionable if Devore, who has insignificant financial resources, would even do as well in 2010 as Mountjoy did in 2006.

So Devore is no threat to Boxer, unlike Fiorina who has the support of the GOP establishment in Washington D.C. and can be expected to mount a heavily funded effort if she is the nominee.

That means the Democrats will have to spend upwards of $20 million saving Boxer, who would normally be safe. But if she is lucky enough to face Devore, she is home free and that $20 million can be spent elsewhere.

That is the key. Democrats are beside themselves right now that the 60 votes they have in the US Senate is not really 60 because it includes the likes of Sen. Joe Lieberman (I-Connecticut) and Sen. Ben Nelson (D-Nebraska. But Democrats have a chance to add to their 60 by picking up open Republican Senate seats in New Hampshire, Florida, Missouri and Ohio in 2010. If they can pull this off, bills like the single payer health care public option and the carbon tax to save the planet that are out of reach now could be passed in 2011.

But Democrats also have to defend their own seats in 2010, and some incumbents such as Sen. Harry Reid (D-Nevada) and Sen. Blanche Lincoln (D-Arkansas) are in trouble. If they have to spend an additional $20 million defending Boxer from the likes of Fiorina, funding the races to pick up additional seats will be much more difficult.

Campbell has already run unsuccessfully for the US senate twice (1992 and 2000) – receiving only 37 percent in his last race.. While he can make a plausible case in the gubernatorial primary (he actually does understand the budget), he has no case to make as a candidate for the US Senate. But if he keeps Fiorina from the nomination, he may play an historic role in helping the Democrats pass their very liberal agenda in 2011.