Later in the evening, a surprise speaker will take the stage in support of Mitt Romney and Paul RyanPaul Davis RyanMcConnell names Senate GOP tax conferees House Republican: 'I worry about both sides' of the aisle on DACA Overnight Health Care: 3.6M signed up for ObamaCare in first month | Ryan pledges 'entitlement reform' next year | Dems push for more money to fight opioids MORE — there is heavy speculation that the speaker will be actor, director and former Carmel, Calif., mayor Clint Eastwood, but the GOP had not confirmed that as of early Thursday morning.

Finally, Sen. Marco RubioMarco Antonio RubioRyan pledges 'entitlement reform' in 2018 Richard Gere welcomes lawmakers' words of support for Tibet Dem lawmaker gives McConnell's tax reform op-ed a failing grade MORE (Fla.), who was seen as a potential running mate for Romney, will introduce the presumed nominee, who will officially accept the nomination and close out the convention.