Maria Corina Machado: the face and fire of Venezuela's opposition

Maria Corina Machado, a 57-year-old engineer with rock-star appeal, became the fearless figurehead of Venezuela's opposition after being barred from challenging strongman Nicolas Maduro in elections last July.

On Thursday, she was "forcibly detained," then released, her team said, after emerging from months in hiding to lead a protest seeking to fire up resistance to Maduro's alleged power grab.

Polled as the most popular politician in Venezuela by far, Machado accepted taking a political...