[asark]

When invoked by laypersons, it usually means "don't run a deficit at all, and cut 'useless' (to me, so far as I know) programs". Arts funding and foreign aid are popular first candidates for the chopping block.

I don't know what it means when politicians say it, aside from being an appeal to the above. Possibly they mean the same thing.

[EDIT] incidentally, it's almost entirely associated with the Right. Unusual to see it brought up as a point in favor of a Democrat.

[EDIT EDIT] awinder probably nailed what it means when politicians say it, and/or why it's an idea some of them have promoted.