Scenes from the trail

Hillary Clinton looks around a post to greet audience members at a campaign launch party at Carter Hill Orchard in Concord, New Hampshire, June 15, 2015. REUTERS/Brian Snyder

Bobby Jindal wears cowboy boots at the Family Leadership Summit in Ames, Iowa, July 18, 2015. REUTERS/Jim Young

Bernie Sanders listens to remarks at the Iowa Democratic Party's Hall of Fame dinner in Cedar Rapids, Iowa, July 17, 2015. REUTERS/Jim Young

Donald Trump arrives for a news conference at the Family Leadership Summit in Ames, Iowa, July 18, 2015. REUTERS/Jim Young

Sisters Sophia (L) and Norah Boice of North Charleston play on seats after Hillary Clinton spoke at a rally at Trident Technical College Conference Center in North Charleston, South Carolina, June 17, 2015. REUTERS/Randall Hill

Supporters of Scott Walker line up to attend a campaign stop in Davenport, Iowa, July 17, 2015. REUTERS/Jim Young

Rick Perry adjusts his tie as he listens to his introduction from the side of the stage at the Freedom Summit in Des Moines, January 24, 2015. REUTERS/Jim Young

Carly Fiorina arrives for a speech before Chamber of Commerce members during a campaign stop in Salem, New Hampshire, July 8, 2015. REUTERS/Brian Snyder

Lindsey Graham holds up his beer after speaking during a campaign stop at Milly's Tavern in Manchester, New Hampshire, July 10, 2015. REUTERS/Brian Snyder

A sign guides guests to a town hall campaign stop with Jeb Bush at the VFW Post in Hudson, New Hampshire, July 8, 2015. REUTERS/Brian Snyder

John Kasich formally announces his campaign for the 2016 Republican presidential nomination during a kickoff rally in Columbus, Ohio, July 21, 2015. REUTERS/Aaron P. Bernstein

Scott Walker attends a dinner during the "Road to Majority" conference in Washington, June 20, 2015. REUTERS/Carlos Barria

Supporters of Jeb Bush knock on doors of the auditorium to gain entrance to his formal announcement of his campaign at a kickoff rally in Miami, June 15, 2015. REUTERS/Carlo Allegri

Marco Rubio autographs a magazine with his picture on the cover after he announced his bid for the Republican nomination during a speech at Freedom Tower in Miami, April 13, 2015. REUTERS/Carlo Allegri

Assorted cookies in support of Rick Perry are seen at a National Press Club luncheon in Washington, July 2, 2015. REUTERS/Yuri Gripas

An attendee arrives at a campaign event for Bernie Sanders in Des Moines, Iowa, June 12, 2015. REUTERS/Jim Young

Hillary Clinton adjusts her make-up before speaking at the Iowa Democratic Party's Hall of Fame dinner in Cedar Rapids, Iowa, July 17, 2015. REUTERS/Jim Young

Jeb Bush runs along the Independence Day parade route in Amherst, New Hampshire, July 4, 2015. REUTERS/Gretchen Ertl

A man waits for the start of a town-hall style campaign stop with Rand Paul in Londonderry, New Hampshire, May 11, 2015. REUTERS/Brian Snyder

Chris Christie gets a kiss from a supporter after he formally announced his campaign for the Republican nomination during a kickoff rally at Livingston High School in Livingston, New Jersey, June 30, 2015. REUTERS/Brendan McDermid

A girl runs across a lawn before former Hillary Clinton appears at a Fourth of July event in Glen, New Hampshire, July 4, 2015. REUTERS/Dominick Reuter

Supporters of Donald Trump wait to see their candidate at a campaign event in Laconia, New Hampshire, July 16, 2015. REUTERS/Dominick Reuter

A Jewish supporter of Hillary Clinton shows off his "Hillary" inscribed yarmulke skullcap before her campaign kick off rally in Franklin D. Roosevelt Four Freedoms Park on Roosevelt Island in New York City, June 13, 2015. REUTERS/Brendan McDermid

Hillary Clinton answers questions from reporters following a campaign town hall meeting in Dover, New Hampshire, July 16, 2015. REUTERS/Brian Snyder

Scott Walker's winnebago drives over a dirt road on his way to a campaign stop in Haverhill, Iowa, July 18, 2015. REUTERS/Jim Young