As long as you can. Demand explanations of their bullshit. Suggest you'll donate (but don't actually do so) if they answer your questions. In other words, treat them like 419eater.com treats Nigerian email scammers.
I got a cold call from somebody connected with Speaker Boner that went something like this.
"We're conducting a public opinion survey, would you like to participate?"
Me: Sure, why not.
"As you know, Speaker John Boehner is out to clean up Washington, cut the deficit, bla bla bla.... He wants to know what you think the 112th Congress' top priority should be."
Me: Well, I think the defense budget should be cut drastically. You cannot be serious about cutting the deficit unless defense is on the table.
"I can't agree with you more. I'll pass it on. Now I'd like you to listen to a one-minute recording of Speaker Boehner, and when it's finished, you'll be directed back so we can get your reaction to it."
Me: OK. (rolling my eyes, but getting the germ of an idea in my head to keep these jokers on the line for awhile, wasting their time)
Speaker Boner goes on about passing bills every week cutting the deficit and killing the "job killing Obamacare. Afterward, I get somebody entirely different on the phone, trying too hard to sound like a swell guy.
"Well, what did you think?"
Me: Not too much.
"Well, as you know, Speaker Boehner is going to (among other things) balance the budget and cut taxes...."
Me: Wait a minute. Are you serious? You're going to pass more tax cuts, and expect to balance the budget? Now, my degree is in computer science, not math, but that just doesn't make any sense. How do you suppose that's going to work.
"Can we count on you for a donation of $100, or maybe $250 so that the Republicans can..."
Me (laughing my ass off): I don't think so. You have a nice day now.
I had them on the line for maybe two minutes or so. Not too bad for being caught be surprise, but I might have done better. Much better. I could have said something like this:
Wait a minute! You haven't asked my question. I want to know how you all expect to balance the budget and cut taxes at the same time. While I have you on the phone, I want to know whose taxes you intend to cut. Mine? Warren Buffet's? The poor schmuck who passes out carts at Wal-Mart? Whose?
Here's another one I thought about after the fact:
Speaker Boehner talks all the time about creating jobs. How was HR3 supposed to accomplish that?
That one would have been fun to hear the answer to. Odds are that the guy on the other end of the phone has no idea what the fuck HR3 is, and will start going on about killing Obamacare, or cutting taxes, or some other talking point, and then you've got him.
You see, the longer you can keep one of the GOP's spokesdrones on the line, the fewer calls he or she gets to make per hour. Make the spokesdrone hang up on you - that's how you win this game. I hung up on them, and let them off the hook. Dumb. Very dumb. Since you now know that the Boner people are just cold calling people, get your questions ready and needle them until they start smoking.