Gingrich gave another terrific speech last night.

He always does. He’s an excellent speaker.

The problem is, you can’t lead by just giving speeches, and because of that Newt is problematic.

Newt’s an idea man. Listen to him and you’ll hear all kinds of great stuff. Last night, for example, he made a great case for zeroing out the capital gains tax. He was great on energy. He talked about moving the U.S. embassy in Israel to Jerusalem (which was a crowd-pleaser, though it’d probably be a good way to get some diplomats blown up).

But since Newt churns out so many ideas and positions, more so than anyone else in the 2012 GOP presidential field, some of them are bound to be clunkers. And because he’s so often undisciplined, he tends to get himself in trouble.

That lack of discipline appears to have cost him his campaign staff. It cost him a lot of support when he stepped in a big pile of bad messaging on the Ryan plan. And it’s the reason why despite those ideas, that creativity and the terrific advocacy he so often gives to the party, he just can’t be taken seriously as a candidate.

It’s a frustrating phenomenon. Really is.