How does that work, anyway? Do they get kicked out if they don't get voted on after X amount of time? Or does it depend upon the amount of votes they do(or don't) get?
In terms of archival processes, there are 3 main factors to whether a card stays or moves to the archive:
1. Current amount of votes on the card (most important factor of them all)
2. Number of cards currently in the Poll
3. Length of duration the card idea has been in said poll
Any card that doesn't have a '*' symbol next to it with 0 votes automatically gets shipped off to the archive (there's no point if the card stays if no one (not even the card author!) wants it to advance).
From then on out, the more cards there are in the polls, the more likely more cards will be sent to the archive, because votes are generally spread out, thus resulting in cards that have fewer votes in comparison to the others. Older cards are obviously taken into account, but any non-recently submitted (*) card is up for elimination after being in the polls for at least a month.
Theoretically speaking, a card stay in the polls for eternity (technically) if they always keep getting second place votes during the forge advancement, but that's very rare, and even then, if that occurs, Card Curators will look at that situation and maybe make a possible exception to advance that card to the next polls if it's currently stuck in the 'limbo 2nd place' position, although that has never happened before...
...oh, and if there are more than 33 cards in a poll, multiple cards can be advanced to the forge (it doesn't apply for forge->armory advancements, however). ^^; Hopefully that explains enough for you Korugar.