Jack Hitt writes for Harpers Magazine and after this I'm going to take the other things he writes with a big grain of salt. He says:

(Ron Paul supporters) were protesting a decision by RNC officials not to seat members of the Maine delegation, which was split between Paul and Romney supporters following rule changes made just prior to the convention. There were energetic shouts of "Aye!" and "Nay!" as a Puerto Rican party functionary - Zoraida Fonalledas, the chairwoman of the Committee on Permanent Organization - took her turn at the main-stage lectern. As she began speaking in her accented English, some in the crowd started shouting "U.S.A.! U.S.A.!"

The chanting carried on for nearly a minute while most of the other delegates and the media stood by in stunned silence. The Puerto Rican correspondent turned to me and asked, "Is this happening?" I said I honestly didn't know what was happening - it was astonishing to see all the brittle work of narrative construction that is a modern political convention suddenly crack before our eyes. None of us could quite believe what we were seeing: A sea of twentysomething bowties and cowboy hats morphing into frat bros apparently shrieking over (or at) a Latina. RNC chairman Reince Priebus quickly stepped up and asked for order and respect for the speaker, suggesting that, yeah, what we had just seen might well have been an ugly outburst of nativism.

Except, the narrative Jack Hitt is pushing conflicts with reality. The chants of "U-S-A" have nothing to do with Fonalledas. Instead, the chanting was an attempt by Mitt Romney fans to drown out Ron Paul fans who were shouting "seat them now" and other things about their delegates.

Jack Hitt even implicitly admits as much, appending an update in which he links to a report by Zeke Miller of BuzzFeed (link):

Loud cries of "Boo" and" Seat them now" filled the convention floor as repeated calls to contest a credentials committee report fell on deaf ears after it passed by a voice vote. A majority of the delegates from six states were required to call for a roll call vote on the credentials report, submitting their intent to do so in writing in advance. Despite Maine the delegates' claims, no such support came from their colleagues from other states.

The boos disrupted the speech of Puerto Rico National Committeewoman Zori Fonalledas, who was set to announce the nomination of Speaker of the House John Boehner as permanent convention chairman.

Priebus repeatedly called on the crowd to silence themselves, as dozens of men wearing earpieces converged on the shouting Paul supporters — some delegates, and even more expressing their displeasure from the arena's upper decks.

As Boehner moved to the report from the Committee on Rules and Order of Business, Paul supporters began shouting "Point of Order," calling on the chair to recognize them for a motion. Boehner shouted over them, as other delegates tried to drown them out with chants of "U-S-A."

Jack Hitt is just seeing what he wants to see, even if it doesn't comport with reality.

But, wait, there's more (link):

Zoraida Fonalledas, the National Committeewoman for Puerto Rico, who is also the chairwoman of the party’s permanent organization committee said to NBC Latino that contrary to reports, she was not the object of "USA, USA!" chants when she stepped up to the podium to announce the RNC committee during the convention’s opening statements, and assured she was caught in the "Ron Paul" convention flap.

"There was a group who wanted Ron Paul delegates to be counted; they were protesting the way it worked out," says Fonalledas, who was about to start making her statement when "USA! USA!" chants can be seen coming from a group of Ron Paul delegates.

"They were not happy with the rules, but we are in a democracy; we had a meeting, they did not have the votes, and we have to unite," she said. Fonalledas says she also said "USA!" as the chants grew louder.

I've included two videos below, the first shows what actually happened: Romney fans were trying to shout down Ron Paul fans. The second video is the one Jack Hitt links, showing an abbreviated version. Watch both, then based on those and the above decide for yourself if you want to trust what Jack Hitt writes.

UPDATE: The brief note - apparently added by Hitt himself - has now changed into something more formal and has moved up to the top of the post from the bottom:

Editor's Note: After this post was written, it was reported on Buzzfeed and elsewhere that the "U.S.A." chant on the convention floor began as a response to chants of "Point of Order" by Ron Paul supporters. An RNC spokesperson denied to Fox News Latino that the chanting was related to Zoraida Fonalledas's nationality.