Elba Esther Gordillo began her career as a school teacher and became one of Mexico's most flamboyant and powerful political operators, displaying her opulence openly with designer clothes and bags.

For years, the 68-year-old union leader beat back attacks from dissidents, political foes and journalists who have seen her as a symbol of Mexico's corrupt, old-style politics. Rivals long accused her of corruption, misuse of union funds and even a murder. But prosecutors had never brought a charge against her until Tuesday, when she was arrested and accused of embezzling $160 million in union funds to pay for everything from a house in San Diego and plastic surgery procedures to her Neiman Marcus bill.

Gordillo was detained as she landed at the Toluca airport near Mexico City on a private plane from San Diego and whisked away by authorities.

Born in the impoverished southern state of Chiapas, Gordillo was just 15-years-old when she joined the National Education Workers Union, then considered a sort of electoral army for the Institutional Revolutionary Party, or PRI, which governed Mexico for 71 years. She followed the path of most Mexican politicians, rising through a series of union, party and government posts. She was a senator for the PRI and also served in Mexico's lower house.

When a strike by dissident teachers led President Carlos Salinas to oust the old boss of the teacher's union in 1989, the job fell to Gordillo, who was widely seen as a reformer.

The union post made her one of the most powerful figures in the PRI at a moment when democratic reforms were starting to erode the party's hold on power, as well as its unquestioning subservience to Mexico's president.

Even before the PRI lost the 2000 election to the National Action Party's Vicente Fox, Gordillo began hedging her bets. She was the guiding force behind the creation of the New Alliance Party, which was based on members of the teacher's union and was once headed by one of her daughters.

She participated in a high-profile discussion group that included prominent social activists and opponents of the government, including Fox. Her friendship with Fox infuriated some PRI officials, who managed to prevent her from becoming leader of the party in 2005. She was expelled from the party a year later for supporting other parties' candidates and for founding the New Alliance.

The party, along with the vast spread of the teacher's union itself, has given Gordillo special leverage. Because it is large enough to swing votes from one large party to another, rivals have negotiated for its backing. Her support was considered key in giving both Fox and Felipe Calderon the presidency, as well as blocking her rival, Andres Manuel Lopez Obrador, from reaching Mexico's highest office.

Critics accused her of amassing more than a dozen properties worth millions of dollars. The newspaper Reforma once published a story analyzing one of her outfits and noting she was carrying a $5,500 purse and wearing $1,200 shoes.

She has acknowledged some of the wealth, saying part was inherited and part she earned through her job that paid her about $6,000 (80,000 pesos) per month.