As his hopes of victory fade the former mayor of Mexico City has talked up the prospect of voter fraud robbing him of victory on July 1 the same accusation he made six years ago when he brought much of the capital to a standstill for weeks. Fueled by a burst of student led opposition to front runner Enrique Pena Nieto of the opposition Institutional Revolutionary Party PRI Lopez Obrador saw a poll rally in late May with one showing him just four percentage points adrift of his rival. That surge has now ended and most polls show him to be at least 10 points behind Pena Nieto. Some recent surveys even show Lopez Obrador to have fallen back behind Josefina Vazquez Mota of the ruling National Action Party PAN. However the 58 year old says his campaign's data show him to be slightly ahead and he has told supporters to look out for a repeat of the tricks he says denied him victory in 2006. Another close finish would raise the risk of a new post-vote crisis and likely trigger legal challenges and street protests. But if Pena Nieto wins by the wide margin many polls are predicting any fraud claims would ring hollow and unrest would likely be short lived and on a smaller scale. Lopez Obrador and his campaign team last week accused the PRI of planning to pay voters to cast ballots for Pena Nieto and asserted that state governors from the centrist PRI had agreed to guarantee their candidate a certain number of votes. Buying votes is a crime. We are going to issue a call to avoid ...