More than 100 of presumptive Republican presidential nominee Mitt Romney's top donors will join him this weekend, a sign that big-money donors — not the small donors that propelled Barack Obama to victory in 2008 — may be the difference-makers in this election.
Ralph Eubanks, director of publishing for the Library of Congress, talks about the new book, "Presidential Campaign Posters," and what has and hasn't changed about campaigning throughout the years.