The curtains closed Thursday on the Republican National Conventions and Ron Paul supporters are tasked with backing a candidate not their own.
Luis LaRotta, a delegate from Texas in favor of Paul, said the nomination of Mitt Romney has him concerned.
"I don't know what to say other than I'm truly concerned, and how are we going to unite the party when people are breaking rules? The RNC rules are like the constitution of the United States."
The GOP announced a rule change Monday to allow the party's presidential nominee to replace his primary opponents' elected delegates with his own supporters. The committee said the purpose was to present a unified front to the American people.
LaRotta says not all Paul supporters will automatically back Romney in Paul's home state of Texas.
"I can't go to my constituents and the people who support me and say vote November Republican and not get some concerned looks. And I can tell you it's not going to be an easy sell. It's going to be tough."
It's expected that some Paul supporters will leave the Republican Party and support Libertarian Party nominee Gary Johnson, the former governor of New Mexico.