Bernie Sanders’s campaign is warning Democrats that Joe Biden is vulnerable to attacks from President Trump, but his team skipped over one obvious weakness: Hunter Biden.

“Donald Trump tonight sent a warning shot to our party: If we nominate a candidate like Joe Biden who has repeatedly tried to cut Social Security and pushed disastrous trade deals, Trump will exploit that vulnerability in an effort to obscure his own record and win the battleground states that could swing the general election,” Sanders campaign manager Faiz Shakir wrote after Trump’s Fox News town hall Thursday.