Randy Evans, an RNC committeeman from Georgia and Rules Committee delegate and lawyer who has worked with the RNC and Trump campaign, has compiled a list tracking delegate leanings at the convention. He estimates that right now, the delegate unbinding effort has about 18 members of the Rules Committee behind it — far short of the 28 needed to get a minority report that merits an up-or-down vote on the convention floor.

But he expects that Lee, who has thus far declined to publicly commit on the movement, could play game-changer as one of the highest-profile members of the committee.

“I think if Sen. Lee stands up in the Rules Committee and says, ‘In the interest of transparency I think the delegates should get their choice,’ I think they get their 28,” Evans said.

Lee has remained noncommittal. The senator’s office on Wednesday said his position has not changed, that he remains undecided as he has repeatedly told reporters. During the primary, he appeared on the campaign trail with both Texas Sen. Ted Cruz and Florida Sen. Marco Rubio, close friends of his, and then endorsed Cruz shortly before Rubio exited the race.