The Texas senator's campaign ran eight delegates for eight committee spots and lost every one, alleging it was "double-crossed" by Kasich supporters.
The Michigan delegation picked one Trump
supporter, Matt Hall, and one Kasich
supporter, Judi Schwalbach, for the two seats on the powerful rules committee. The Cruz
campaign lost votes for both seats.
The rules committee seats have become highly coveted prizes for their role in shaping a contested convention in Cleveland. After the delegates are selected in each state, they meet as a group and pick the members of four convention committees, the most important of which is the rules committee, which will ultimately decide who can be nominated president.
Michigan Cruz leader Saul Anuzis said they were "double-crossed" by Kasich's campaign. The Kasich delegates were supposed to vote with Cruz delegates, he said, but switched sides and voted with Trump behind closed doors Saturday afternoon.
Kasich's delegate director in Michigan, Jeff Timmer, said the Cruz campaign broke their end of the deal when they tried to win all eight delegation seats.
He said they finished their slate of Trump and Kasich candidates about 10 minutes before walking into the delegation meeting.
"The Cruz campaign tried a takeover and they failed miserably," Timmer said. "It backfired and they ended up with nothing. There's been all these reports about how they're out-organizing everybody. Not here."
Trump's national delegate director, Brian Jack, called it a "big win" for Trump.
"The most important votes occurred this afternoon -- we went 5-0. Five delegates for Mr. Trump ran for committee assignments; all five were elected," Jack said.
He added, "This was a big win for Team Trump. We won 25 delegates from Michigan last month, and now, at least 25 supporters of Mr. Trump will be delegates to the Republican National Convention."
Much of the focus in the delegate battle has been on the sheer numbers of delegates themselves, with Cruz outgunning Trump in states like Louisiana and Colorado. But the delegations themselves -- usually an afterthought -- have become battlegrounds on the path to an expected convention fight in Cleveland.
Trump and Cruz had formed an alliance behind the scenes to deny Kasich the seats needed to get himself even nominated in Cleveland, but the skirmish in Michigan marked an apparent shift in alliances.
"Do they have a bigger deal? I don't know what they're trying to do," Anuzis said. "I think they won a short-term victory here on committee assignments. We were approached by several of their delegates who were very upset with how it was done in the process and I think that will help us long term on the floor."
Of Michigan's 59 delegates selected Friday and Saturday, Trump supporters filled 25 spots, Cruz supporters filled 17 and Kasich supporters took another 17 -- although it was unclear who all the delegates were permanently aligned with.
But as the votes were taken behind closed doors, they appeared to break mostly along campaign-allegiance lines. Trump supporter Mary Balkema won her contest against Cruz state chairwoman Wendy Day for a seat on the credentials committee. And Kasich supporter Chuck Yob -- the father of Republican operative John Yob -- beat Cruz supporter Rep. Justin Amash for the other spot on the credentials committee.
Each Cruz candidate managed to swing a few more votes above the 17 delegates awarded to him in Michigan, but nowhere close enough to win any seats.
The victory for Chuck Yob could put him in place to oversee a challenge to his son John Yob's bid to be a delegate from the Virgin Islands.
Elsewhere on Saturday, Democrats are caucusing in Wyoming
, while Republicans in Colorado are choosing delegates
for the party's convention in July.