Twenty minutes, a microphone, lots and lots of Iowans, and the eyes of the nation. That's what greets political hopefuls who take the stage at the Des Moines Register Political Soapbox. This year, the Soapbox at the Iowa State Fair will host more than 20 presidential candidates, both Democratic and Republican, as they vie for the nation's highest office.

Dwight D. Eisenhower in 1954 was the first presidential candidate to campaign at the State Fair, and presidential candidates have flocked to the fair, amid agriculture competitions and fried food, ever since.

In 2007, Barack Obama drove the fair's bumper cars with his then-6-year-old daughter, Sasha. In 2011, on the Register's soapbox, Mitt Romney said "corporations are people." And four years ago, then-presidential hopeful Donald Trump didn't appear on the Soapbox, but gave helicopter rides to kids near the fair.

While the fair allows candidates to don cowboy boots and eat giant turkey legs in the hot August sun, the Soapbox provides a space for real political discussion. Face-to-face with Iowans, candidates must explain and defend their policy positions in front of the live audience. The Des Moines Register will livestream all of the speeches at DesMoinesRegister.com/Soapbox.

Dates and times are subject to change, and more speakers may be added.

This schedule will be updated online if changes occur.

Thursday

12:45 p.m.: Democrat Steve Bullock, the sitting governor of Montana.

Democrat Steve Bullock, the sitting governor of Montana. 1:30 p.m.: Democrat Joe Biden, a former vice president and former U.S. senator from Delaware.

Friday

9 a.m.: Democrat Julián Castro, secretary of Housing and Urban Development under President Barack Obama and the former mayor of San Antonio.

Democrat Julián Castro, secretary of Housing and Urban Development under President Barack Obama and the former mayor of San Antonio. 10:30 a.m.: Democrat Andrew Yang, a businessman.

Democrat Andrew Yang, a businessman. Noon: Democrat John Delaney, a former U.S. representative from Maryland.

Democrat John Delaney, a former U.S. representative from Maryland. 1:30 p.m.: Democrat Marianne Williamson, an author and activist.

Democrat Marianne Williamson, an author and activist. 2:15 p.m.: Democrat Tulsi Gabbard, the U.S. representative for Hawaii's 2nd Congressional District.

Saturday

9 a.m.: Democrat Jay Inslee, the sitting governor of Washington.

Democrat Jay Inslee, the sitting governor of Washington. 10:30 a.m.: Democrat Kamala Harris, a U.S. senator from California.

Democrat Kamala Harris, a U.S. senator from California. 11:15 a.m.: Democrat Tim Ryan, the U.S. representative for Ohio's 13th Congressional District.

Democrat Tim Ryan, the U.S. representative for Ohio's 13th Congressional District. 12:45 p.m.: Democrat Amy Klobuchar, a U.S. senator from Minnesota.

Democrat Amy Klobuchar, a U.S. senator from Minnesota. 1:30 p.m.: Democrat Joe Sestak, a former U.S. representative from Pennsylvania and retired vice admiral in the U.S. Navy.

Democrat Joe Sestak, a former U.S. representative from Pennsylvania and retired vice admiral in the U.S. Navy. 2:15 p.m.: Democrat Kirsten Gillibrand, a U.S. senator from New York.

Democrat Kirsten Gillibrand, a U.S. senator from New York. 3 p.m.: Democrat John Hickenlooper, a former governor of Colorado.

Democrat John Hickenlooper, a former governor of Colorado. 3:45 p.m.: Democrat Elizabeth Warren, a U.S. senator from Massachusetts.

Democrat Elizabeth Warren, a U.S. senator from Massachusetts. 4:30 p.m.: Democrat Cory Booker, a U.S. senator from New Jersey.

Sunday

11:15 a.m.: Republican Bill Weld, a former governor of Massachusetts.

Republican Bill Weld, a former governor of Massachusetts. 1:30 p.m.: Democrat Tom Steyer, a businessman and political donor.

Democrat Tom Steyer, a businessman and political donor. 3 p.m.: Democrat Michael Bennet, a U.S. senator from Colorado.

Democrat Michael Bennet, a U.S. senator from Colorado. 3:45 p.m.: Bernie Sanders, a U.S. senator from Vermont and an independent seeking the Democratic nomination.

Bernie Sanders, a U.S. senator from Vermont and an independent seeking the Democratic nomination. 4:30 p.m.: Democrat Bill de Blasio, mayor of New York City.

Tuesday

1:30 p.m.: Democrat Pete Buttigieg, mayor of South Bend, Indiana.

Aug. 17

Noon: Democrat Seth Moulton, the U.S. representative for Massachusetts' 6th Congressional District.

No one is currently scheduled to speak on Monday; Wednesday through Friday; and Aug. 18.

The following candidates have been invited to the Des Moines Register Political Soapbox but have yet to schedule appearances: Democrat Wayne Messam and Republican Donald Trump.