He's only 20 years old which means he registered like 2 years ago. You do realize that you don't have to pass a lie detector test to register for a political party in this country right? He also gave donations to a known far left group "actblue" and he donated to Biden. Far left Dem groups have been telling their followers to register republican for years now also, that's a mess with the republican vote bit but also could come in handy for other far worse purposes.
'The gunman who shot
Donald Trump last night is a 20-year-old registered Republican who donated to
Joe Biden.'
'State voter records show Crooks was a registered Republican. According to US media, when he was aged 17 he donated $15 to the liberal ActBlue political action committee on January 20, 2021 -
Biden's Inauguration Day.'
https://www.dailymail.co.uk/news/ar...mp-gunman-revealed-registered-republican.html