生成一篇介绍美国总统乔·拜登的文章。
Joe Biden is the 46th President of the United States. He was Vice President under President Barack Obama from 2009 to 2017. Biden also served in the US Senate for 36 years, representing the state of Delaware. Throughout his career, Biden has focused on issues such as healthcare, education, climate change, and civil rights, and he has been known for his advocacy on behalf of the middle class. Biden has emphasized the need for unity and healing in America and has pledged to work towards these goals during his presidency.