Clint Eastwood's speech at the Republican National Convention on Thursday, Aug. 30 has received mixed reactions from Hollywood, music stars and the President himself.

The "Unforgiven" actor, who was the RNC's surprise guest speaker, delivered his remarks with an interesting concept - he addressed an empty chair pretending President Obama was sitting in it while commenting on several current policies.

A long list of celebrities critiqued Eastwood's speech on Twitter: HBO "Newsroom" star Olivia Munn, CNN's Piers Morgan, Seth Meyers, Chris Rock, Adam Levine and even the President.

President Obama captioned a photo of himself sitting in a chair marked "The President" with "This seat's taken."

"The Voice" judge Adam Levine wrote: "Clint Eastwood has gone f**kin nutterbutters yo" while his co-star and fellow judge Blake Shelton tweeted "I. Love. Clint Eastwood."

Celebrity tweet reactions to Eastwood's unconventional speech are as follows:

Piers Morgan: "Still reeling from that #Clint performance - sooooooooo weird."

Zachary Quinto: "Is clint eastwood meant to instill confidence in republicans?! I am legitimately scared of his talking to imaginary Obama."

Patton Oswalt: "'If Clint Eastwood ever talks to a chair on national TV, people will need a way to reassure each other' - inventor of Twitter, March 2006."

Roger Ebert: "Clint, my hero, is coming across as sad and pathetic. He didn't need to do this to himself. It's unworthy of him."

Zach Braff: "Still can't tell if Clint was hallucinating or President is really invisible now."

Charlie Daniels: "Clint Eastwood made my day."

Seth Myers: "When Clint woke up this morning he saw that Obama was gone from the chair...Or was he still there!?!?!"

Olivia Munn: "No, that's not the set up to a joke. It's not even a joke."

Chris Rock: "Clint Eastwood on the phone with Obama now: 'It all went according to plan, sir.' #RNC #GOP2012."

Roseanne Barr: "Clint eastwood is CRAY."

Mia Farrow: "What WAS that thing Clint Eastwood just did? How could they let it happen?"

Simon Pegg: "Maybe Clint is a sleeper agent for the Democrats sent in under deep cover to make the Republicans look stupid. No wait, that's Romney."

Shannon Woodward: "From now on, every time I sit in a chair, I'll know I'm really sitting in Obama's lap #ourlittlesecret #getoffmylawn."

Tags: rnc Republic National Convention 2012 mitt romney Paul Ryan Clint Eastwood President Obama Adam Levine Blake Shelton