Of the four living former U.S. presidents, so far only Jimmy Carter has agreed to attend Donald Trump’s inauguration on Jan. 20. With less than a month to go, the 92-year-old Democrat confirmed that he will attend the ceremony, while George H.W. Bush, also 92, cited his age as the reason he will not attend. Both George W. Bush and Bill Clinton have yet to RSVP to the inauguration, indicating that they will wait until after the new year to make a final decision. All four of the men attended Barack Obama’s first inaugural in 2009. In a video taped for the Democratic National Convention, Carter described Trump as a candidate “who seems to violate some of the most important moral and ethical principles on which our nation was founded.”