Maybe she was just a little sentimental? She was at her alma mater and her college professor says, "Welcome home, we are so proud of you". Honestly, that might make me tear up a little to. She is entitled to feel an emotion without a political agenda behind it.
So if Obama gets a little emotional is everyone doing to say he's doing it for votes?
Sorry, Sing, I have to disagree. Presidents need to have their emotions under tight control at all times. They have the ability to send our kids into harm's way, and they have the codes for the nuclear football. Presidents who don't control their emotions well get us into ill-advised wars (see Bush, George W.).
If she was having an unguarded moment, then it makes her less competent to be President. If she was using her emotions for political purposes, all well and good, but she better be ready for someone to call her on it.