Hillary Clinton. AP Photo/Matt Rourke Hillary Clinton's campaign ignored pleas from staff members for the candidate to boost her efforts in Michigan and Wisconsin, two unexpected battleground states, The Huffington Post reported Wednesday.

The two states, considered safely Democratic by virtually all pollsters ahead of the election, swung for Donald Trump on Election Day, securing the Republican his shocking victory.

One senior operative told The Huffington Post that in Michigan, which Clinton is on track to lose by about 12,000 votes, her campaign's canvassing operation was one-tenth the size of Democratic candidate John Kerry's in 2004.

The Huffington Post reported that, according to one organizer, the campaign sent canvassers to a trailer park in Flint, Michigan, unaware that the park had burned down.

"It was arrogance, arrogance that they were going to win," a senior operative told the publication. "That this was all wrapped up."

In Wisconsin, local campaign officials were forced to raise $1 million in last-minute get-out-the-vote funds after Clinton's national campaign declined to provide it, operatives told The Huffington Post.

Clinton's Wisconsin office also reportedly lobbied for the campaign to send African-American surrogates to boost Democratic turnout in Milwaukee. Clinton received 39,000 fewer votes in Milwaukee County than Barack Obama did in 2012, and she lost the state by about 27,000 votes, thanks to lower turnout in three key counties.

"There are only so many times you can get folks excited about Chelsea Clinton," a Wisconsin Democrat told The Huffington Post.

Trump ramped up his efforts in Michigan in the final weeks of the campaign, making multiple stops there, including his final campaign appearance, which stretched into the early morning of Election Day.

An average of polls conducted before the election showed Clinton with a 3.4-point lead in Michigan and a 6.5-point lead in Wisconsin. The two states are worth a combined 26 electoral votes — still not enough for Clinton to reach the 270 threshold. She also lost Pennsylvania, which hadn't swung Republican in a presidential race since 1988.

Clinton's campaign has pinned the loss on the FBI director, James Comey, who announced 11 days before the election that the bureau was renewing its investigation into Clinton's use of a private email server. A campaign director wrote in an email last week that the announcement most likely helped depress voter turnout.

Comey's subsequent letter clearing Clinton of any wrongdoing, issued two days before the election, may have energized Trump's supporters in turn, the director said.

Read the Huffington Post report here.