If she’s campaigning for him and making speeches for him, then what she’s saying is fair game. Since he doesn’t have a track record, he’s so scripted and isn’t really saying anything, just soaring rhetoric with no substance and the MSM refuses to ask him the tough questions, then what his wife says may be (notice, people I said may be) a window into his views. At the very least, he can be asked if he’s as bitter and whiny about their student loans as she is:

Obama, his party’s presidential front-runner, and his wife, Michelle, were asked in an interview aired Monday on ABC’s “Good Morning America” about an online video last week by the state’s GOP taking her to task for a comment some considered unpatriotic.
“The GOP, should I be the nominee, can say whatever they want to say about me, my track record,” Obama said. “If they think that they’re going to try to make Michelle an issue in this campaign, they should be careful because that I find unacceptable, the notion that you start attacking my wife or my family.”
He called the strategy “low class.”