As usual, it would be better to quote this Digby post verbatim, but let me just give you the relevant section from the article in question:
(Loretta) Sanchez, Orange County's only Democratic member of Congress, voted in 2002 against giving President Bush authorization to invade Iraq. More recently she voted to begin pulling troops out within 90 days.
Tuesday night Sanchez said she could not support the protesters (who want to cut funding for the war) because the $145 billion in Iraq war funding was in the same bill that would provide money to build the C-17 aircraft in California.
"I never voted for this war," she said. But "I'm not going to vote against $2.1 billion for C-17 production, which is in California. That is just not going to happen."
Sanchez has been consistently against the war, and she cannot be fully blamed for protecting her constituents. But she's constrained by the fact that a major military contractor in her district has a gun to her head. Particularly in California, but all over the country really, the massing of the war machine has a definite impact on policy. They put their factories in all these different districts, so that shuttering an obsolete weapons system will be met with enormous resistance. This ensures that you can never decrease military spending or even keep it the same. And eventually, all these systems have to be justified. Through war.
This is approximately why the nightly news has all of these ads for Lockheed Martin and Boeing on them. I can't buy a 757, but Boeing can keep that news network in line by threatening to drop their ads if they stray from the party line.
It's just another way that big money distorts our politics. Sanchez's statement makes it quite clear that the "power of the purse" is not about stopping anything. It's about funding all kinds of things that have been set up over many years to keep politicians like Sanchez in line. She really does have to answer to her constituents --- many of whom make their living off the military industrial complex dime. You can't blame her.
I don't even think public financing will stop this. You're talking about thousands of constituents' jobs. And California embodies this problem as much as any state in the union. It's something we really have to think about. How do we, after 60 years of massive military buildup, put this genie back in the bottle?
(This isn't limited to defense, by the way, John Dingell's attempt to upend CAFE standard legislation preferred by the Speaker comes from him protecting his constituents, just as resistance to gas taxes comes from legislators protecting theirs.)