WASHINGTON (AP) — President Joe Biden is out to win votes by scoring some laughs at the expense of Donald Trump, unleashing mockery with the goal of getting under the former president’s thin skin and reminding the country of his blunders.

Like a comic honing his routine, the Democratic president has been testing and expanding his jokes over the past few weeks. It started with jabs about his Republican opponent’s financial problems, and now Biden regularly pokes fun at Trump’s coiffed hair, his pampered upbringing and his attempt to make a few extra bucks by selling a special edition of the Bible.

The jokes are the latest attempt to crack the code on how to clap back at Trump, whose own insult comedy schtick has redrawn the boundaries of what is acceptable in modern politics. Few have had much luck, whether they try to take the high road or get down and dirty with Trump, the presumptive Republican nominee for president.