And almost 12 hours after he shook up Twitter pre-dawn, Trump returned with a new tweet invoking Clinton's famous ad from her 2008 campaign portraying her as the best candidate to pick up an urgent call at the White House at 3 a.m.
In the 2012 election, nearly 700,000 Iowans voted early.
"It's definitely going to be amped", Westerfield said of the campaign's effort to hand out absentee ballot requests and encourage people to vote early in person.
Democratic presidential candidate Hillary Clinton gestures as she takes the stage during a campaign stop in Des Moines, Thursday, Iowa, Sept. 29, 2016.
Clinton said that, in particular, she would "love to see" young people turn out to vote in big numbers.
In all, 37 states permit some form of early voting, either in person or by mail.
Pelosi said Thursday she is "very confident that the makings of a wave are there", but noted the election is still more than five weeks away.
"I want this election to be about something, not just about somebody", Clinton said, as she talked about climate change, equal pay for women, paid family leave, jobs, education, economic growth and more.
In Des Moines, Mrs Clinton planned a speech focused on childcare challenges faced by middle-class families.
Hillary Clinton says a new report alleging that Donald Trump may have violated the USA embargo on communist Cuba is just more evidence that he puts his own interests ahead of the nation's. He told reporters in Raleigh that he'd been studying the first Clinton-Trump debate and practicing against a dramatized version of Trump running mate Mike Pence, played in prep sessions by Washington lawyer Bob Barnett.
However, in a nod to the concerns expressed by some Trump allies that he was insufficiently prepared, his campaign and the Republican National Committee released a "TRUMP Debate Preparation Survey" ahead of his second showdown with Mrs Clinton.
On Friday, Trump said Clinton had been "set up by a con" in holding up Machado "as an "angel" without checking her past, which is awful!"
Working from 33 offices throughout the state, the Clinton campaign and Iowa Democratic Party have joined forces to elect the first female president of the United States.
The survey, a gimmick meant to engage supporters online, asks whether Trump should use the second debate to criticize Clinton for her policies on terrorism, economics and trade - questions sure to elicit an enthusiastic "yes" from Trump backers.
Donald Trump doesn't take advice from Senate Minority Leader Harry Reid, but the Nevada Democrat has some for him anyway: Don't bring up former President Bill Clinton's marital infidelities.
Johnson sighed, saying after a strained pause, "I guess I'm having an Aleppo moment".
Mr Trump was also facing fresh questions on Thursday about business opportunities he explored in the late 1990s in Cuba, apparently in violation of the U.S. embargo on the communist island. Not to vote, but to watch her parents, Ehtridge and Katrina Netz, cast their ballots.
President Barack Obama handily won Iowa in the past two presidential elections, leaving Democrats with a high bar to clear ahead of Election Day, Nov. 8.
Iowa has gone Democratic in six of the last seven presidential elections.
In 2008, Obama, then a little-known senator from IL, bested this year's Democratic presidential nominee Hillary Clinton in the primary and defeated U.S. Sen.