[peyton randolph]

Undecided = spineless or liar.

[hiredhand]

I sort of doubt that somebody who claims to be undecided would lie about it...Ya never know, but I doubt it.

But I think you nailed it with the spineless part. The only thing I could add is spineless and snivelling.

[newgeezer]

Undecided = spineless or liar.

I hasten to add a third possibility (perhaps closely related to the first): Clueless.

[Lou L]

Undecided = spineless or liar.

I would also add, "or completely ignorant."