 -- With the selection of Maine delegates this weekend, Ted Cruz procured further support as he aims to win the nomination at what could possibly be a contested Republican National Convention in Cleveland this summer, but his campaign came under fire for subverting a unity deal for its own benefit.

Maine RNC committeeman Alexander Willette, a Donald Trump supporter, told ABC News that 19 of the 20 national delegates selected Saturday to represent Maine at the GOP convention were "endorsed by the Cruz team." The 20th delegate selected, Gov. Paul LePage, has endorsed Donald Trump. Maine will send 23 delegates to Cleveland this summer. According to GOP rules, the remaining three delegate slots will be filled by Maine State Party Chair Rick Bennett, Willette, and RNC committeewoman Ashley Ryan.

Cruz won the Maine caucuses on March 5, and was subsequently allotted 12 delegates. Trump was given nine, and John Kasich 2. But the actual delegates were selected this weekend, at the state’s convention in Bangor.

Maine’s delegates are bound to a candidate on the first ballot, but free agents on the second, making their support crucial for Cruz, whose hopes of winning the nomination by procuring the necessary 1,237 delegates rest on a contested convention in Cleveland.

Willette said all three campaigns had agreed to propose a unity slate that would represent the choice of Maine voters. But, he said, before the delegate names had been nailed down on Friday, the Cruz campaign said they were going another way.

Maine GOP Party chairman Richard Bennett told ABC News the unity slate would have potentially included elected officials, including LePage and Sen. Susan Collins.

Bennett is part of the Maine delegation but said he does not know whom he will support on a second ballot, if there is one.

A senior adviser to the Cruz campaign said discussions for a unity ticket occurred, but never finalized. The Cruz campaign's state leadership team wanted to run their own slate and that's what the campaign decided to do in Maine. The adviser told ABC News that the campaign is working with Republicans from all parts of the party nationwide. For example, the adviser said, Iowa Gov. Terry Branstad, who bashed Cruz in the run-up to Iowa Caucuses, is a delegate for Cruz now.

LePage accused the Cruz campaign of backstabbing and betraying the people of Maine.

Trump’s convention manager Paul Manafort said on "Fox News Sunday" that the Cruz campaign "steamrolled" the process.

Cruz's campaign defended its actions and credited the party's "grassroots base."

"Ted Cruz stands with the grassroots who made our caucus victory in Maine possible. He will always defend the interests of the people who elected him over the will of establishment politicians. And let's not forget, Gov. LePage has endorsed Donald Trump, his reaction is exactly what you’d expect from the Trump campaign, whining and complaining," Cruz spokeswoman Catherine Frazier said. "Ted Cruz continues to win elections, and the credit goes to the grassroots base of our party who have come behind him and are uniting Republicans behind his campaign."

Cruz's sweep of the Maine delegation once again showcases his campaign's organizational prowess and understanding of the complex delegate process that some are arguing is eluding the Trump campaign.

In the past month, Cruz has won a majority of delegates at conventions in Wyoming, North Dakota, and Colorado, adding further ammunition to his argument that even though he currently trails Trump by nearly 300 delegates, he can beat the frontrunner on subsequent rounds of voting at a contested convention if neither candidate heads to Cleveland with the requisite 1,237.

"It was clear from the March 5 caucus that the Cruz campaign was better organized in Maine and that carried through to the convention," Bennett told ABC News. On the convention floor, he explained, the Cruz campaign had volunteers carrying pictures of their slate so attendees would know who to select.

“I don't think the other campaigns had that level of organization,” Bennett said.