Mr. Obama, the son of a black man from Kenya and a white woman from Kansas, was raised in Hawaii with the help of his maternal grandparents, who were white. When he pursued the White House in 2008, Mr. Obama talked on the campaign trail about his extended family of siblings, nieces, nephews and cousins of "every race and hue."
Mr. de Blasio, who is white, is married to Chirlane McCray, who is black, and the couple have two teenagers. Mr. de Blasio has characterized his family as a symbol of the city's diversity. The couple's son Dante, who sports an eye-catching Afro, was featured in a campaign commercial that some political observers say helped Mr. de Blasio win the most votes in the primary.
To get where they are today, both Messrs. Obama and de Blasio beat well-known, front-running female opponents whose elections would have been historic. Mr. Obama, 52 years old, edged out Hillary Clinton, who aspired to be the nation's first female president, for the 2008 Democratic nomination. In the city's Democratic primary earlier this month, Mr. de Blasio, also 52, beat City Council Speaker Christine Quinn, who sought to be the city's first female and first openly gay mayor.
In a news release issued Monday by Mr. de Blasio's campaign, Mr. Obama said Mr. de Blasio had "bold, courageous ideas that address the great challenges of our time," including proposals for more prekindergarten classes, expanded after-school programs, new below-market rate housing and the preservation of local hospitals.
"Progressive change is the centerpiece of Bill de Blasio's vision for New York City, and it is why he will be a great mayor of America's largest city," the president said in the news release.