The Electoral College is poised Monday to select Donald Trump as the next president of the United States, despite efforts to disrupt the 227-year-old process that so far appear to have resulted in just one openly rogue voter. Still, Democrats and Republicans on Sunday spoke with some uncertainty about the anticipated outcome.

“We expect everything to fall in line,” Reince Priebus, White House chief of staff in the incoming Trump administration, told “Fox News Sunday.”

Electors will convene in state capitals across the country Monday to make the results of the Nov. 8 election official.

In most presidential election years, the Electoral College vote would essentially be a formality. But electors have been facing pressure for weeks from anti-Trump forces to upend the November results; protests also are expected at state capitals on Monday.

While the efforts stand little chance of succeeding, those factions have been fueled by Democratic presidential nominee Hillary Clinton's win in the popular vote. She won roughly 2.6 million more ballots than Trump but lost the Electoral College vote.

Trump got more Electoral College votes by winning many of the smaller, less-populated states in the Midwest and South, along with the big coastal state of Florida and traditionally Democratic-leaning Pennsylvania and Wisconsin.

Trump and Clinton also split the six most populous states.

Trump needs 270 electoral votes Monday. And the state victories put him in line to get 306 of the 538 -- with each state getting one vote for each House and Senate member. The three remaining votes go to the District of Columbia.

Priebus, who still runs the Republican National Committee, which is trying to keep count of the apportioned or “pledged” votes, cited the only known and so-called “faithless” balloter, who lives in Texas and whose vote goes to Trump but plans to vote for another, yet-to-be-named Republican.

“But other than that, we're very confident that everything is going to be very smooth,” said Priebus, noting a massive petition drive to get electoral voters to cast ballots against Trump and the alleged harassment of some of the voters, particularly in Arizona, where Trump won 49 percent of the vote, compared to 45 percent for Clinton, which entitles him to all 11 electoral votes.

Arizona elector Robert Graham told Fox News on Saturday that the 11 electors have received hundreds of thousands of emails telling them not to vote for Trump and that he’s received information that some of the other 10 have been followed or have received a death threat.

“It’s out of hand when you have such … a small group of people that is pushing so hard against millions if not hundreds of millions of people who still appreciate this whole system,” said Graham, chairman of the Arizona Republican Party. “The Electoral College is part of the Constitution.”

All swore to party officials that they will back Trump, even though they're not legally bound to do so, and plan to hold to that pledge.

Trump responded to the reports of elector harassment and intimidation Sunday.

“If my many supporters acted and threatened people like those who lost the election are doing, they would be scorned & called terrible names!”

There is no federal law on electoral votes. Some states bind their voters -- often state party officials -- to the popular vote. But the penalties for violations are minor, such as being disqualified from future balloting.

On Sunday, John Podesta, Clinton campaign chairman, suggested that 37 electoral voters bound to Trump could defect, which would be enough to create at least a tie and send the vote to the GOP-controlled House, where Trump would still likely win.

Podesta, as he has in recent days, pressed the argument on NBC’s “Meet the Press” that Russians hacking the emails of Democrats during the election led in part to Clinton’s loss.

He also made a last-minute argument that members of the Electoral College should have an intelligence briefing about the hackings before voting Monday.

“I assume that our electors are going to vote for Hillary Clinton,” Podesta said. “But the question is whether there are 37 Republican electors who think that either there are open questions [about the purported Russian hackings] or that Donald Trump … is really unfit to be president. … And I guess we will know that … tomorrow.”

The Associated Press tried to reach all 538 electors and was able to interview more than 330 of them. Many reported getting tens of thousands of emails, calls and letters asking them to vote against Trump.

But the canvass found overwhelming support for the system, and the nominee, among Republican electors. The AP found only one pledged to Trump who will refuse to vote for him but did not identify him as the voter in Texas.

The Associated Press contributed to this report.