Raese, who was soundly defeated by Byrd in the 2006 U.S. Senate race, said he believes the current climate is much more favorable for a political outsider.
"It appears to me the American public has had about enough," Raese said Thursday.
"There wasn't the outrage that there is today," he said of his 2006 election defeat.
Raese has been known in past races -- including a near-upset of Sen. Jay Rockefeller in 1984 -- for his brash comments and outrageous campaign ads.
Raese said the timing of his announcement -- barely 30 hours before today's 5 p.m. filing deadline -- was influenced by U.S. Rep. Shelley Moore Capito's official notice on Wednesday that she would not run for the Senate.
"I don't like to run against any Republicans, period," Raese said.
While Raese was the first Republican to file for the unexpired term Thursday, over the course of the day, he was joined by nine other Republican hopefuls.
"We've got a team now," said Raese, who quipped that he had not anticipated enough Republicans filing to field a baseball team.
While his immediate focus will be on the Aug. 28 special primary, Raese said his ultimate aim is a Nov. 2 special election showdown with Gov. Joe Manchin.
In his initial comments, Raese has attempted to portray Manchin as a liberal who, as a U.S. senator, would be closely aligned with President Obama, Senate Majority Leader Harry Reid and House Speaker Nancy Pelosi.