She didn’t become a Republican as far as I know.
Neither did Lyndon LaRouche, but after the Dems told him for the third time to **** himself he finally exited the Democratic Party, and lo and behold, a certain number of Republicans decided that they liked him, including Ronald Reagan.
Tulsi is our generation's Lyndon LaRouche and I expect we will be force fed reams of her conspiracy theories just as soon as she lands that sweet gig at Fox "News" Channel.