It's a thumb-on-the-scales type thing. The story floats at the bottom of the front page, and its timer is reset IIRC. The votes still need to come organically, but at least a good story will stand a chance.
I've had several submissions put in the second chance queue. Some take off, some don't. There are a few I plan to keep putting in rotation myself every few months, at least for a while. (Not on any particular schedule, but as I'm reminded of them, often from other relevant discussion.)