But that kind of authority didn't hold much sway when it came time for his presidential portrait.
"He listened very thoughtfully to what I had to say before doing exactly what he always meant to do", he said.
"What I was always struck by when I saw his portraits was the degree to which they challenged our ideas of power and privilege", President Obama said at the unveiling ceremony, complete video of which is available on the Smithsonian website.
He described the portrait, which depicts him sitting on a wooden chair against a colourful, leafy backdrop, as "extraordinary", adding: "It's my great honour to be here". "I was humbled by this invitation, but I was also inspired by Barack Obama's personal story; that sense in which both he and I both do have that echo of single parents, African fathers, that search for the father, that sense of twinning".
Amy Sherald, who painted Michelle Obama's portrait, was featured as part of a touring exhibition previous year of the winners of the Smithsonian National Portrait Gallery's Outwin portrait competition.
Wiley's naturalistic portraits often address the portrayal of young African-American men in contemporary culture.More news: Skiing Robots Crashing into Things is Our Favorite Winter Sport
A different set of portraits of the former first couple will eventually hang in the White House, according to the Associated Press.
The room cheered after Wiley and Obama pulled down the curtain to unveil the portrait.
The choice of contemporary artists fueled interest in the event. Wiley and Sherald are the first African-American artists to receive the honor of painting presidential portraits for the National Portrait Gallery.
Both Obamas chose black artists who've been praised by Kim Sajet, director of the National Portrait Gallery.
"I was anticipating - hoping for - a bolder, more incisive image of the strong-voiced person I imagine this former first lady to be", Cotter said in his review.
Wiley, who is based in NY, is known for vibrant, large-scale paintings of young African-Americans, according to a biography provided by the gallery.