There was an election for the Benicia (CA) City Council this past November. It gives a good lesson in current politics. First, I should point out that Benicia is the home to the Valero Refinery and also that it still has some outlying areas for new home developments.
Valero Refining Company gave $35,000 to a group euphemistically called "Coalition for Responsible Government" (meaning, it seems, responsible to corporate interests). West Coast Homebuilders, owned by developer Albert Seeno, gave the same group $15,000.
Between Nov. 2 and Nov. 7, the group spent $31,000 on fliers, phone calls, and signs supporting two "pro-growth, corporate" candidates and $13,000 opposing the "slow-growth, people-oriented" candidate.
Note that most of the money was spent in the last week before the election. As posters here have pointed out, it is the advertising and push right before the election that has the most effect. In Pombo's case, this will be TV and radio ads, as well as those fliers that always picture him as "Mr. Greenjeans". Political consultants know that most voters generally don't pay attention until just before the election, and that they can be easily influenced by a big push at that time.
So the two pro-corporate candidates had lots of money (for a small city race) due to their support from an oil/gas company and a developer. The corporate-sponsored group used the money to promote their candidates and beat up on the one they did not like.
Of course, those two won, and the other guy lost.
I am mentioning this here not to criticize Benicia (actually a very nice small town), but as a microcosm of the Pombo race. Big oil/gas/development money has been pouring into Pombo's coffers, there will be a "just before the election" push to hammer Filson or McNerney, and to make Pombo look like "Mr. Good Guy/Mr. Security/Mr. Green", and if nothing has been done on the Dem side to counter this or reframe Pombo before the crucial last week, the voters will dutifully march into the polling booth and vote for the image of Pombo conjured up by the corporate advertising dollars.