It's a common refrain of Rudy Giuliani's that leadership involves doing things that are unpopular. Here's an ABC News article in which Giuliani says:
Leadership is about sometimes doing the things you know are right, and then it's your job to educate the public, as opposed to just, you know, taking a CNN poll or a Bloomberg poll or a Fox poll and let that run the country.
Apparently, this principle extends to answering phone calls from your wife while addressing the National Rifle Association. According to the Fox News / Opinion Dynamics poll Marc Ambinder cites here, a whopping 81 percent of voters would prefer that presidential candidates wait until finishing their speech before taking a cell-phone call.