Alexander Vilf / Pool / RIA Novosti / Reuters Mexico's President Enrique Pena Nieto gets into a car upon his arrival a day before the G20 Summit in St. Petersburg, Russia, Sept. 4, 2013.

Embattled Mexican President Enrique Peña Nieto got a welcome gift this week when Congress passed his education reform bill despite massive protests by teachers. But another present may have dropped into his lap, this one courtesy of Washington: It’s this week’s report that, according to yet more secret files leaked by intelligence contractor Edward Snowden, the U.S. National Security Agency (NSA) spied on Peña Nieto’s e-mails during his presidential campaign last year.

Nothing generates more domestic and regional sympathy for a Latin American leader than being the target of a yanqui affront — especially yanqui espionage. Peña Nieto still has a loaded legislative agenda ahead, including a measure to allow private investment in Mexico’s oil industry for the first time in 75 years. Even if the new NSA revelations don’t help him push those reforms through, they certainly won’t hurt him. Mexicans, after all, are perhaps more sensitive than anyone to Washington’s interventionist history in its hemisphere. As Mexico City radio journalist Antonio Morales told the America TeVe show “A Mano Limpia” in Miami this week, “When we hear reports like this, it’s like having lemon juice poured into an open wound.”

Brazil feels it too. According to Sunday’s report on Globo TV out of Rio de Janeiro, the leaked files show that the NSA had also intercepted President Dilma Rousseff’s e-mails and telephone calls. Her government calls it “an unacceptable invasion of our sovereignty,” and Rousseff is reportedly considering canceling her upcoming state visit to the U.S. (On Thursday she postponed an advance team’s visit to Washington because, as aides said, she is still “furious.”) Meanwhile, Rousseff, who has dealt with her own massive anti-government protests — and plummeting approval ratings — all summer long, is suddenly seeing her poll numbers bounce back. Again, the NSA scandal couldn’t have hurt her — and may have been just what the doctor ordered with a presidential election looming next year.

But Mexicans and Brazilians aren’t just irritated by the idea that the U.S. has been spying on the leaders of Latin America’s two largest countries. These days, diplomats around the region tell me, they also see the espionage as Washington’s panicked response to Latin America’s increasing independence from U.S. hegemony in the Americas. In Peña Nieto’s case, Mexicans know that Washington was bothered by his campaign pledge to dial down the militarized intensity of Mexico’s U.S.-backed drug war, which raised U.S. fears that he’d go soft on drug mafias. In Rousseff’s case, Brazilians are bound to consider the NSA monitoring a yanqui reaction to Brazil’s recent foreign policy clashes with Washington, especially on issues like Iran, as the South American giant aims to be more of a regional counterweight to the U.S.

When Snowden files were leaked earlier this summer indicating that Brazil was the NSA’s chief Latin America focus of general communications surveillance, the Obama Administration had an easier time explaining itself: Given past evidence that the Brazil-Paraguay-Argentina border area has been a magnet for foreign terrorists, the U.S. was simply conducting due post-9/11 diligence. But the White House and State Department have been far less forthcoming this week about espionage involving the Brazilian and Mexican heads of state. And that could undermine Obama’s new efforts to re-engage Latin America — where China is making big economic inroads — after what critics call his indifference toward the region during his first term.

Still, security experts suggest that while the political outrage is understandable, the governments of countries as large as Mexico and Brazil shouldn’t be so shocked. “There were things about the surveillance that could have been handled more diplomatically, especially since these things are lightning rods for fears about the Big Brother to the north,” says Johanna Mendelson Forman, a cyber-security expert and scholar-in-residence at American University in Washington. “But Brazil is now the world’s sixth largest economy. In an age when we take it as a given that the communications of major countries like ours and theirs are invaded every day — by countries like China, I might add — using sovereignty as a shield seems naive.”

So, thanks to Snowden, did the U.S. simply get caught doing what everybody does — including Mexico and Brazil? A former NSA official also tells me that even if the agency did gather presidential chatter as part of its surveillance sweep, it was more likely to study and file away the origins of e-mails and calls rather than their contents. But that doesn’t square with Globo’s report that the NSA did pore over the details of some of Peña Nieto’s e-mails.

In the end, analysts like Mendelson Forman are probably right: The Obama Administration may have to swallow Latin America’s acute regional sensitivity to revelations like these. But emerging powers like Brazil and Mexico may have to resign themselves to the more high-stakes game of cyber-intelligence they’ll keep confronting on a bigger world stage. In the meantime, Peña Nieto and Rousseff can probably reap political fruits from the yanqui affronts.