U.S. Sen. Marco Rubio, R-Florida, speaks at an event in Ankeny, Iowa, as he campaigns for President on Monday, August 17.
U.S. Sen. Rand Paul, a Kentucky Republican who is also an ophthalmologist, gets suited up so he can perform cataract surgery in Haiti on Monday, August 17. While the humanitarian trip was not technically part of Paul's presidential campaign, he invited a small number of political journalists and at least one prominent donor to join him.
Louisiana Gov. Bobby Jindal, a Republican presidential candidate, poses for a selfie at the Iowa State Fair in Des Moines on Saturday, August 22.
Republican presidential candidate Jeb Bush waits backstage before speaking at an education summit in Londonderry, New Hampshire, on Wednesday, August 19.
Republican presidential candidate Ben Carson, in the blue shirt, rides the Sky Glider with a reporter while touring the Iowa State Fair on Sunday, August 16.
Another Republican presidential candidate, Ohio Gov. John Kasich, is reflected in a mirror while speaking at a town-hall meeting in Salem, New Hampshire, on Wednesday, August 19.
A woman at the Iowa State Fair listens to U.S. Sen. Lindsey Graham as the South Carolina Republican campaigns for President on Monday, August 17.
Democratic presidential candidate Hillary Clinton speaks at a town-hall meeting in Las Vegas on Tuesday, August 18.
New Jersey Gov. Chris Christie, a Republican presidential candidate, tosses a pork burger on the grill at the Iowa State Fair on Saturday, August 22.
A card marks the seat of Republican presidential candidate Rick Santorum, who delivered a speech on immigration policy Thursday, August 20, at the National Press Club in Washington.
Carly Fiorina, a Republican presidential candidate, talks to children while they look at a cow made of butter Monday, August 17, at the Iowa State Fair.
U.S. Sen. Bernie Sanders, a Democratic presidential candidate from Vermont, attends a fundraiser in Chicago on Monday, August 17.
Wisconsin Gov. Scott Walker, a Republican presidential candidate, holds up a $1 bill while talking to voters at a campaign stop in Sunapee, New Hampshire, on Thursday, August 20.
U.S. Sen. Ted Cruz, R-Texas, prays during the "Rally for Religious Liberty" in Des Moines on Friday, August 21. Cruz, a conservative firebrand, was the first Republican to announce his campaign for the presidency.
A visitor at the Iowa State Fair uses a corn kernel to vote in a straw poll on Thursday, August 20.