John Kerry, the former secretary of state and 2004 Democratic presidential nominee, is endorsing Joe Biden for president, buoying the former vice president’s argument that his international experience should be a deciding factor for voters in 2020. The Biden campaign rolled out Kerry’s endorsement as it continues to hammer President Donald Trump as a dangerous and erratic commander in chief and head of state. The campaign hammered the argument Wednesday with an online ad featuring video of other world leaders mocking Trump at a Buckingham Palace reception held alongside a NATO summit. Backing: Joe Biden – who embraced Mary Rose Brown, 93, during a meet and greet on his No Malarkey! bus tour at Ellsworth Community College in Iowa Falls, Iowa – is now being endorsed by John Kerry Into the race: John Kerry will campaign for Joe Biden, who is struggling in polls in Iowa ‘I’ve never before seen the world more in need of someone who on day one can begin the incredibly hard work of putting back together the world Donald Trump has smashed apart,’ Kerry, 75, said in a statement. That echoes applause lines Biden, 77, uses often as he campaigns. ‘The next president will inherit…