One of the biggest legal challenges former US president Donald Trump faces relates to more than 300 classified documents found at his Mar-a-Lago estate in Florida in an FBI raid last year. This week, President Joe Biden has been drawn into a similar saga with 10 documents from his time as vice president found in an office he’d used after leaving the job. And overnight, the White House confirmed that more documents – a “small number” – were found at Biden’s residence in Delaware. He’s expressed surprise and says he doesn’t know what the documents relate to, but he’s cooperating with a Justice Department investigation. The mishandling of classified documents is a big no-no that can lead to criminal charges, and Biden had been scathing of Trump’s predicament. Meanwhile, Trump has wondered aloud on social media when Biden’s “many houses” will be raided…