The conventions have historically been held inside convention centers , but in recent decades the two major parties have favored sports arenas and stadiums to accommodate the increasing capacity , the former because indoor arenas are usually off-season outside of WNBA sites , allowing plenty of time for preparation ( the major political parties have avoided baseball stadiums ever since the 1992 Republican National Convention at the Houston Astrodome forced the Houston Astros to play 26 consecutive road games ) . Bids for the 2008 Republican National Convention , for example , were required to have a facility with a seating capacity of at least 20,500 people , including a convention floor of about 5,500 delegates and alternates ; the Xcel Energy Center in Saint Paul , Minnesota was eventually selected . Meanwhile , approximately 84,000 people attended the last day of the 2008 Democratic National Convention at Denver 's Invesco Field at Mile High . The last day of the 2012 Democratic Convention was originally also scheduled for an outdoor football stadium , but was moved indoors due to weather concerns . The last non-sporting venue to host the Democratic National Convention was San Francisco 's Moscone Center in 1984 . In 1996 , the San Diego Convention Center in San Diego became the last non-sporting venue to host the Republican National Convention
2008 Republican National Convention
2008 Republican National Convention
United States presidential nominating convention