What was HBO thinking?

Who does the network think will tune in for a two-hour documentary on Barack Obama’s presidential campaign?

Maybe die-hard Obama fans feeling nostalgic for the time when his poll numbers were higher and his potential seemed as limitless as the sky.

“By the People: The Election of Barack Obama,” getting an Election Night premiere, is slick and well-produced and either two years late or two years early for Obama’s campaign committee.

It opens with Obama enjoying the 2006 midterm elections.

“I love elections. It’s so much fun. It’s even more fun when you’re not on the ballot,” he smiles.

Then it picks up in February 2007, after he declares his candidacy, and tracks his efforts in Iowa.

You know how the story goes; filmmakers Amy Rice and Alicia Sams have to make the journey compelling enough to re-live it. Their purported access to our sitting president is questionable. You should only have to sit through so many shots of Obama glad-handing supporters.

As primary season wears on, Obama seems to be a supernaturally level fellow, cool in victory and defeat.

The closest he comes to showing even a trace of irritability occurs as he sits on a campaign bus.

“How can the Patriots [team stats] game be blacked out?” he asks his aides.

If the filmmakers don’t get much spontaneity or insight from Obama, they find it in his supporters.

“By the People” demonstrates how his campaign captured the imagination of the young, people of color and those who had felt frozen out by George W. Bush’s eight years in office.

The filmmakers also fare better in vignettes with Michelle Obama. She recalls how she sat down with her husband and questioned what a campaign would do to their family before finally deciding, “We are now running for president.”

Later, Michelle works an undecided voter by turning on the charm: “You know you love me,” she grins. The Obama girls bounce up and down after one victory.