On the campaign trail: Obama, Romney visit key swing states

It was a busy day on the campaign trail for all four candidates in the race to the White House.

With less than three months until Election Day, President Obama and Mitt Romney both continue bus tours in key swing states.

Romney in Ohio and Obama in Iowa.

We now know two key speakers during the Republican National Convention. Florida Senator Marco Rubio will introduce Mitt Romney and New Jersey Governor Chris Christie will give the keynote address.