MILWAUKEE— Florida Sen. Marco Rubio, a finalist in former President Donald Trump's search for a vice presidential running mate, arrived at the Republican National Convention on Tuesday with praise for the GOP nominee despite him ultimately picking Ohio Sen. JD Vance to join him on the ticket. Fox News Digital caught up with Rubio outside the Fiserv Forum in Milwaukee where he reacted to Trump's triumphant first public appearance in the convention hall since surviving an assassination attempt on Saturday. "I've never seen so much energy and enthusiasm behind any candidate in American history, in my time alive," Rubio said, predicting we would see more of that high energy and enthusiasm in the remaining days of the convention. TRUMP ANNOUNCES OHIO SEN JD VANCE AS HIS 2024 RUNNING MATE Rubio predicted Trump's highly anticipated Thursday speech would unify Americans around his "core message" that's "always been the same." "There's nothing scandalous about it. He wants to put America, and Americans, above anything else. And, if our president is not going to do that, then who is?" he said. "I think that is the one thing that we actually should be unified over, and I hope, and I believe, that is the one thing we'll take away from Thursday night." Trump announced Vance as his running mate in a Monday post on Truth Social while the convention was in the process of officially nominating him as the Republican candidate. TRUMP VP PICK JD VANCE: WHAT ARE HIS VIEWS ON TAXES, DEFICITS, ENTITLEMENTS "After lengthy deliberation and thought, and considering the tremendous talents of many others, I have decided that the person best suited to assume the position of Vice President of the United States is Senator J.D. Vance of the Great State of Ohio," Trump wrote. Vance was warmly welcomed while appearing on the convention floor during his nomination process later in the day, where he stood alongside members of the Ohio delegation. Ahead of his selection announcement, Rubio and North Dakota Gov. Doug Burgum were both informed they would not be picked, according to multiple sources. CLICK HERE TO GET THE FOX NEWS APP "JD Vance is a fantastic choice. Americans will soon see this is an incredibly intelligent and talented man who is completely committed to making America great again. Vote for #TrumpVance2024 so we can unite our people and save our country!" Rubio wrote in a post on X following Trump's announcement. Get the latest updates from the 2024 campaign trail, exclusive interviews and more at our Fox News Digital election hub.