Who is the current President of the United States as of October 2023?

As of October 2023, Joe Biden is the current President of the United States. He assumed office on January 20, 2021, succeeding Donald Trump. Biden's presidency has been marked by various significant events and policies, addressing issues such as the COVID-19 pandemic, economic recovery, climate change, and social justice.

Understanding the context of the other figures listed helps clarify why they are not the current president. Barack Obama, who served two terms from 2009 to 2017, finished his presidency before Biden took office. Donald Trump served as president from 2017 to 2021 and was succeeded by Biden. Kamala Harris is the Vice President, not the president. Thus, given the timeline and context of U.S. presidential history, identifying Joe Biden as the president accurately reflects the political landscape as of October 2023.