Justifying pure science research: Discovery

How do you convince politicians to fund basic research?

On The West Wing there is an episode Dead Irish Writers in which many things are happening simultaneously. One is that Sam Seaborn [White House Deputy Communications Director] is meeting with a Princeton Physics Professor, Dr. Millgate who is dying of cancer but trying to secure funding for the Superconducting Super Collider. It features the following excellent dialogue.

Sam Seaborn: Okay. I said I'd do this, but it's likely he's gonna say this is an unaffordable luxury. 

Millgate: We're losing the race for discovery, Sam. For discovery. Tonight, it's just me and you. 

Sam Seaborn: That doesn't really sound like enough. 

Millgate: No.

Then in a later scene

Senator Enlow: If only we could only say what benefit this thing has, but no one's been able to do that. 

Dr. Millgate: That's because great achievement has no road map. The X-ray's pretty good. So is penicillin. Neither were discovered with a practical objective in mind. I mean, when the electron was discovered in 1897, it was useless. And now, we have an entire world run by electronics. Haydn and Mozart never studied the classics. They couldn't. They invented them. 

Sam Seaborn: Discovery. 

Dr. Millgate: What? 

Sam Seaborn: That's the thing that you were... Discovery is what. That's what this is used for. It's for discovery.

Is this why in Australia the main source of research grants for people like me are "Discovery Grants"?