By E. EDUARDO CASTILLO and MARK STEVENSONMEXICO CITY (AP) â¿¿ The arrest of Mexico's most powerful union leader echoes the hardball tactics of Mexico's once-imperial presidency while pushing forward an education reform that Enrique Pena Nieto has made a centerpiece of his new administration. Elba Esther Gordillo, known for flashing her Hermes handbags and heels, stood behind bars Wednesday in a grim prison in eastern Mexico City as a judge read off charges of embezzlement and organized crime. The arrest sidelined a woman who had tried to mobilize teachers to block a schools shake-up designed to end her control over hiring and firing of teachers across the country. It also sent a message to other union bosses and business magnates: Don't get in the way of Pena Nieto, whose Institutional Revolutionary Party has newly returned to the power it held for seven straight decades, when incoming presidents often crushed those who challenged them. "This is an old tactic, let's hope that it doesn't just stop there, as it did in the past, when a single case was enough to calm things down and add legitimacy" to presidential power, said Jose Antonio Crespo, an analyst at the Center for Economic Studies. "Let's hope this doesn't stop and that it becomes something more systematic, for which there is a burning need." Crespo was referring to the business magnates and union bosses who have built fortunes and political power by dominating whole sectors of the economy. Like Gordillo, their resistance could be an obstacle to Pena Nieto's pledges to modernize and open up Mexico's economy. But the tough message of Tuesday's arrest may have been enough. Gordillo, whose 1.5 million-member National Union of Education Workers organized protests against Pena Nieto's education reform signed into law this week, was pulled off a plane arriving from San Diego late Tuesday and taken to Mexico City's women's prison.