Rumer Willis is in a celebratory mood, as are many Americans this week, as Joe Biden took over as the 46th President of the United States. Rumer proclaimed that she's "proud to be an American again" and also sent out a staunch warning to those who feel like picking a fight with the eldest daughter of Demi Moore and Bruce Willis. 32-year-old Rumer took to Instagram this week while dropping a new photo of herself stretching her arms up to the heavens while making her happiness known to all.