President Obama is trying to become the third president in a row to win back-to-back terms. In 2008, he trounced Republican John McCain both in terms of raw votes and Electoral College votes. In 2012, he faces presumptive GOP nominee Mitt Romney amid a highly polarized electorate, a slow economic recovery, and with some of his prior supporters complaining about his military engagement in Libya and reversal on the suspected terrorist detention center at Guantanamo Bay, Cuba. His running mate is Joe Biden, former US senator from Delaware and Obama's vice president in his first term.
- Written by Glen Johnson, Boston.com politics editor