Donald Trump was formally made president-elect in an Electoral College vote that saw 10 electors attempt to become faithless electors -- a rarity in American politics.

Trump won the election with 304 electoral votes. Two electors in Texas chose not to vote for him, instead backing Ron Paul, Texas congressman and presidential candidate and Ohio Gov. John Kasich.

Hillary Clinton won 227 electoral votes. Five electors chose not to vote for her -- four in Washington State and one in Hawaii.

Three of the Washington electors voted for Colin Powell. One voted for Faith Spotted Eagle, a South Dakota Sioux leader who took part in the protests against the Dakota Access Pipeline. The Hawaii elector voted for Sen. Bernie Sanders.

In addition, electors in Colorado, Maine and Minnesota initially declined to vote for Clinton. Alternates replaced two of them, and one ended up changing his vote.

Electors are not required by the Constitution to vote for a candidate. Founding Fathers such as Alexander Hamilton said the Electoral College could act as a bulwark against bad candidates.

But states and parties have made it so electors must vote for the candidate who wins the popular vote.

In Florida, each party submits a slate of electors during the primary. When a candidate wins the election, the state's governor chooses the 29 electors from the winning party's slate.

Trump got all of Florida's 29 votes, including Kat Gates-Skipper's. The Polk county resident was an organizer for the Trump campaign.

She said in the last few weeks she'd received thousands of phone calls and emails demanding that she flip her vote.

"And then they started sending me Christmas cards," Gates-Skipper said. "I'm like, really? So, it's not going to make a difference to me, because I had a duty, an honor, I signed an oath, and being the Marine that I am, I keep that in the civilian world, so they just wasted their time with me."

In the case of Texas, four electors had to be replaced before voting even took place because they either didn't show up or were disqualified.

The Texas electors were also bombarded with pleas from anti-Trump voters for weeks to flip their votes.

Texas Elector Chris Suprun had made it plain before the vote that he would not support Trump. Suprun said he cast a ballot for Kasich based on principle.

Protesters rallied at state capitols throughout the country, demanding that electors flip their votes, citing Trump's business conflicts of interest and Russia's suspected influence on the election in Trump's favor.

"If they think there's something wrong about the election, then they have a constitutional mandate to not cast that vote. It's our last check and balance," said Kim O'Connor, who traveled to Tallahassee from Tampa Monday to protest the vote.

In New York, all 29 electoral college members voted for Hillary Clinton. Among the electors was Clinton's own husband, former President Bill Clinton.

"I've never cast a vote I was prouder of," the former president said. "You know, I've watched her work for two years, I watched her battle through that bogus e-mail deal, be vindicated at the end when Secretary e-mails came out, she fought through that, she fought through everything."

The electors also all donated their $15 compensation to the New York Immigration Coalition -- an apparent dig at Trump, who promised a tougher stance on immigration.

The last time an elector voted against the prospective president-elect was in 1972, when a Virginia Republican voted for a Libertarian over President Richard Nixon.

Lawmakers will formally certify the Electoral College results in a joint session of Congress on Jan. 6.

President-elect Donald Trump will be sworn in on Jan. 20.

Information from reporter Troy Kinsey, Spectrum News NY1 and Spectrum News Austin was used in this report.