Felipe Calderon

3 independents poised to shake up Mexico's presidential race

The bronco, the jaguar, and the former first lady: These three outsiders appear destined for Mexico's July 1 ballot as the first independent candidates to seek the presidency in generations, the result of a reform seen as a victory for democracy in the country.

The mavericks have cleared the demanding hurdle of collecting nearly 1 million signatures to qualify and — pending official word from election authorities — are sure to sure to inject color into the race by challenging candidates from the well-heeled, state-funded parties that are widely perceived as corrupt political machines.

While early polls suggest they have slim chances of winning, the independents could...