With next Tuesday's swearing-in of President-elect Barack Obama just days away, the man of the moment has paid tribute to his daughters Malia and Sasha in an emotion-filled letter.
In the document, due to be published in the US press on Sunday, the proud father tells the youngsters how they have inspired his ascent to the White House and apologises for the time he's spent away from them.
"I know that it hasn't always been easy for you and mum," writes the 47-year-old statesman. "And as excited as you are about that new puppy, it doesn't make up for all the time we've spent apart."
He continues: "When I was a young man, I thought life was all about me… Then you came into my world, with all your curiosity and those smiles that never fail to fill my heart.
Suddenly all my big plans for myself didn't seem so important anymore. I soon found that the greatest joy in my life was the joy I saw in yours. And I realised that my own life wouldn't count for much unless I was able to ensure you had every opportunity for happiness and fulfilment in yours… That's why I ran for president."