Toxic tacos latest misstep in Mexican race Enrique Peña Nieto, the slick and youthful frontrunner in Mexico's presidential elections, may still be streets ahead of the opposition, but his Institutional Revolutionary Party (PRI) is doing its best to narrow the gap. At least, that is how it looked when 709 people suffered a vigorous bout of Montezuma's revenge after eating egg and rice tacos with sauce that were handed out at a political rally of one of the party's would-be candidates for congress. Lázaro Mazón Alonso, health minister of southern Guerrero state, where the incident occurred, said that the afflicted suffered severe diarrhoea, fever and vomiting, El Universal newspaper reported. There were no fatalities. While the centrist, opposition PRI was mulling that gaffe, Mexico's two other mainstream parties were hard at work creating one of their own. The slogan "One Mexico for All" may not leap off the page, but for the ruling conservative National Action party (PAN) and the leftwing Democratic Revolution Party, it is one worth defending. On Tuesday, Gustavo Madero, who heads the PAN, accused the founder of the PRD of plagiarising the phrase for the benefit of his own party. "Cárdenas copies the slogan "One Mexico for All" used in PAN advertising," Mr Madero railed on his Twitter account. As it turned out, Cuauhtémoc Cárdenas, the political icon and target of Mr Madero's accusations, has been using the slogan for about a decade. Mexico's presidential race may not have officially started - campaigning for the July 1 poll begins in earnest at the end of March - but to judge by this week's theatrics, you would never know it. Few would bet against the bickering getting more boisterous and the faux pas more frequent over the coming months. Jorge Zepeda, political analyst and journalist, argues that underneath all of this lies a serious message: the election is not yet won. Until a few months ago, Mr Peña Nieto, telegenic former governor of the state of Mexico and Cliff Richard lookalike, was so far ahead in the polls that most people thought the race was over before it had even begun. Andrés Manuel López Obrador, the swarthy leftwing veteran was lagging badly, and Josefina Vázquez Mota, the petite economist and mother of three, had yet to emerge from her party's primaries race. "The months leading up to the election looked as if they were going to be a virtual victory lap around the country," says Mr Zepeda. What all of this tells you is that the race is still on. For many observers, the change began with what is now going down in history as Mr Peña Nieto's "December mistake." This was when he sauntered up to Guadalajara's annual book fair, Latin America's largest, and then experienced a mental "non-traction" moment as he scrambled to name three books that had influenced him. "The Bible is one of them," he blurted after some verbal skating. "I haven't read all of it, just some parts," he clarified to the heavily Catholic audience. Of course, the other candidates have had their share of bloopers. One dates back to when Mr López Obrador was candidate in the last contest, but has slipped by relatively unnoticed. Having lost the 2006 election by just 0.5 percentage points to current centre-right President Felipe Calderón, Amlo, as Mr López Obrador is more affectionately known, cried foul, held a mass rally in Mexico City's main square and proclaimed himself Mexico's "legitimate president." Six years later, and once again on the roster of leading presidential candidates, Amlo may have overlooked one small detail: in Mexico there is no re-election.