"Let's not forget that we are running against authoritarianism and power, and they are capable of anything," says Mexico's leading opposition candidate, Xochitl Galvez, as the polls close in what calls an "extraordinarily high voter turnout". The ruling party's candidate, Claudia Sheinbaum, a former Mexico City mayor and a scientist by training, led her by 17 percentage points in opinion polls ahead of the vote. SOUNDBITE