Happening

Talking with Katie Couric the other day, Secretary Clinton said "I happen to think it's appropriate that . . . we do this in a careful, thoughtful way."

What does it mean when people interject "happen to" between "I" and "think" or "believe"?

I think it averts the knee-jerk tendency to disagree with any unqualified statement. Instead, it invites listeners to agree. Yes, I believe that too. Who wouldn't?!