I believe in the Democrat Party, the extremists that take the label of "liberal" are not invited to the table, so it is rare for the weirdoes to get on the ticket and only "mainstream" Democrat candidates are on the ticket.
John Kerry, Algore = non-weirdos?
Obama isn't a weirdo, but he
is ideologically pure for the dems.
Dem ticket is usually hard left, repub ticket is usually slightly right of middle- at least during my lifetime.
Either way doesn't matter- they all believe in big government solutions.