WASHINGTON — (CNN) Donald Trump is expected to win Tuesday’s Pennsylvania Republican primary in a landslide, but the size of his all-important delegate haul figures to be a mystery that could stretch all the way to the convention floor in Cleveland this summer.

Leading most Pennsylvania polls by double-digits, the billionaire is a near lock to carry the 17 delegates awarded to the winner of the statewide vote.

But the process is more complicated for the remaining 54. That’s because they are essentially elected on the honor system.

Voters first select their preferred candidate — that’s the state-wide vote.

Then, voters in each of the 18 congressional districts pick three delegates for the convention.

Many of those delegates have have pledged their support to Trump, Ted Cruz or John Kasich, but the catch is that they are technically unbound and beholden to nobody — not the voters, candidates or Republican Party.

The picture looks brightest for Trump, who could do well among the unbound delegates, according to CNN interviews with 135 of the 162 candidates on the ballot.

About 25% say they’ll support the front-runner, another 42% say they’ll support their district’s choice.

This bodes well for Trump, who is poised to win most of the state’s congressional districts.

Twenty percent of respondents said they will support Ted Cruz, while 11% said they planned to remain uncommitted until a later date.

The Cruz campaign is urging supporters to back write-in candidates in the 10th and 17th districts.

None of the hopefuls told CNN they planned to support John Kasich.

But those delegates can still vote any way they like, and some people are happy with that setup given the possibility of a contested convention where every delegate’s vote will matter.

Calvin Tucker, who is running to be a delegate out of the 2nd congressional district, is uncommitted and told CNN that if elected he will not make a decision until July.

“I’m not going to give up any leverage at this point,” he said.

Most states bind delegates on the first ballot at least through a primary, caucus or convention.

As Trump seeks to hit the 1,237 delegates needed to clinch the nomination, he can count the bound delegates.

But the only way to know how these 54 Pennsylvania delegates actually vote will be when they cast their ballots in Cleveland.

The madcap format now has regular citizens trying their hands as political candidates, free to say almost anything but required to follow through on precisely nothing.

How they break in Cleveland, if the Republican race goes to a contested convention, could go a disproportionately long way in deciding the next GOP president nominee.

On Sunday night, the Trump campaign hosted an organizing call with all 41 of their delegate candidates.

On Monday, they ramped up distribution of their list at a campaign event in West Chester.

But with elections in 18 different districts, some with only three names on the ballot and others with more than a dozen candidates, the process isn’t easy for any of the candidates.

Neither Cruz or Trump were able to fill a full slate of 54 candidates across the state.

And it’s clear the convoluted system is causing some confusion, even with the campaigns.

“If Trump isn’t your guy, then I am not your gal,” said Lynne Ryan, a candidate from the state’s third congressional district.

But even as the state’s odd bylaws have made her a minor celebrity — Trump thanked her in a tweet over the weekend — Ryan told CNN she disapproved of the process.

Like Ryan, Arnold McClure is listed on Trump’s slate. But even with the campaign’s stamp of approval, he remains unsure how he’ll vote if elected on Tuesday.

“I have promised to vote for the winner of the 5th Congressional District popular vote and I expect it to be Trump,” he told CNN in email.

“The Trump people chose to endorse me,” McClure wrote, “not because of a promise I made, but because I told them whoever wins the popular vote in the 5th will get my vote until hell freezes over. If any deals are done, it will be done with someone else’s vote.”