You can also get tickets at that link.
I Read some local media online posts & parking may be a problem: Only 1200 spaces at the airport. The airport manager says a shuttle service will be arranged by the White House, but no details are available yet. I’d think the only large lot that could do the job would be the lot @ the SIU Arena. But, then who in the area has enough buses? Crowd projections are 10k - 20k people. Given the area, I’d say 10k - 12k, but, I also read that people are coming from as far as the Chicago area. Hmmm...