Actually, the way it works (at least from what I saw) is that the security stations on the way to the library have a list of people who are guests or VIPs. People on the list arrived anytime they wanted and there was a reception area for when they arrived. They were escorted in, to the rotunda and escorted out.
From what I gathered, public officials and politicians, among others, were on that list and came and went at their leisure.
Around 10:30 last night there were a few cars that were pulling up to see the President.
I'm sure the respect accorded to Kerry was on account of the general nature of the Reagan adminstration who were volunteering to help out, and stood in direct contrast to any kind of respect conservatives would be shown and a similiar liberal event.
Hopefully this VIP list will become public, there's a lot of very un-Reaganesque hatred here that needs to be dished out it seems!