On January 20, 2007, following the ouster of President Maaouya Ould Sid'Ahmed Taya in the August 2005 military "coup d'état", Boulkheir announced his candidacy in the March 2007 presidential election. In the election, held on March 11, he placed fourth, receiving 9.79% of the vote. On March 19, he backed Sidi Ould Cheikh Abdallahi for the second round, despite the fact that he was part of the Coalition of the Forces for Democratic Change along with the other second round candidate, Ahmed Ould Daddah. Abdallahi won the election, and on April 26, 2007, Boulkheir was elected as President of the National Assembly, receiving 91 votes from the 93 deputies present.