Potential 2016 candidates ride in Iowa
Wisconsin Gov. Scott Walker, center, rides in a Roast and Ride event hosted by freshman Sen. Joni Ernst, R-Iowa, June 6, 2015, near Boone, Iowa. Ernst is hoping the event, which featured a motorcycle tour, a pig roast and speeches from several 2016 presidential hopefuls, becomes an Iowa Republican tradition.
Scott Walker
Wisconsin Gov. Scott Walker greets guests before participating in a Roast and Ride event hosted by freshman Sen. Joni Ernst, R-Iowa, June 6, 2015, near Des Moines, Iowa.
Ready to ride
Possible Republican presidential candidate and Wisconsin Gov. Scott Walker prepares to ride in Iowa Sen. Joni Ernst's inaugural Roast and Ride event June 6, 2015.
Joni Ernst
Sen. Joni Ernst, left, R-Iowa, hosts her inaugural Roast and Ride event. She poses with one of the event guests June 6, 2015.
Riders
Iowa Sen. Joni Ernst and Wisconsin Gov. Scott Walker lead the pack in riding from Des Moines, Iowa, to Boone June 6, 2015.
Ben Carson
Neurosurgeon-turned-Republican presidential candidate Dr. Ben Carson speaks with a supporter in Iowa June 6, 2015.
Carson backers show support
Supporters of retired neurosurgeon Ben Carson's presidential campaign show their enthusiasm June 6, 2015.