At the Republican National Convention, delegates are bound by Republican Party of Virginia rules to vote as instructed on the first ballot. However, delegates could always vote as they wished and the RPV does not have any sanction or punishment that accrues to delegates who vote as they choose.
In the past, delegates always voted on the first ballot as instructed by the RPV rules. Therefore, the issue has never arisen or been debated.
There is a State law that says a delegate must vote as instructed by the RPV. Should a delegate not vote as instructed, that person would be guilty of a misdemeanor and may be prosecuted.
A Federal District Court ruled on Monday, July 11th that a State law may not be used to enforce Party rules. The Judge asserted that a political Party is a private organization and the State has no business being involved in the operational workings of such an organization.
That means that delegates are still bound by RPV rules, but the police power of the State may not be used to enforce those rules.
It is unknown if the Court ruling will affect the Convention.