SANTIAGO, Chile (AP) — Michelle Bachelet nearly doubled her conservative rival's votes in the first round of Chile's presidential election, but her center-left coalition fell short of the gains in Congress needed to keep many of her promises.

The moderate Socialist, who was Chile's first female president from 2006 to 2010, beat nine candidates in Sunday's vote and is widely expected to win a Dec. 15 runoff over her childhood friend, Evelyn Matthei. With nearly all ballots counted Monday, Bachelet had 47 percent of the vote to Matthei's 25 percent.

Bachelet, 62, has vowed to raise corporate taxes to fund a sweeping overhaul of the education system that now puts quality schooling out of economic reach for many.

She also favors legalizing abortion in some cases, says she wants to "open a debate" on gay marriage and hopes to overhaul the electoral system and constitution imposed by the 1973-1990 dictatorship of Gen. Augusto Pinochet.

Sunday's vote put some of those reforms within her grasp, but she may have to negotiate on others, at the risk of angering supporters and reviving the angry street protests that marked the past two years.

Bachelet's New Majority coalition has the votes in Congress needed to raise taxes, but it lacks the super-majorities of 60 percent to change the electoral system or 67 percent to change the constitution.

Education reform would require 57 percent approval in Congress, and it appears that Bachelet has that number as long if she can count on Camila Vallejo and three other student protest leaders newly elected to the legislature.

The key may be their willingness to compromise. The vision of education reform they fought for in the streets could be watered down to meet the demands of the centrist edge of Bachelet's wide-ranging coalition, which pulls together centrist Christian Democrats and Communists, veteran politicians and street protesters.

"I can't see elected students voting against reform, but they also won't endorse something they don't want," said Marta Lagos, head of the Mori polling company. "So the dispute is also going to be in the fine print not the reform."

Already, the Communists are vowing to keep "one foot in the street" to press for change. That might mean rowdy protests that could damage her popularity.

"We'll just have to see if the Communist Party is on board with negotiating with the right or if it turns its back and jumps off the victory wagon," said Bernardo Navarrete, a University of Santiago political scientist.

"The big tension for Bachelet will be how the Communist Party behaves."

Bachelet began campaigning just hours after the vote results were announced. She visited a poor neighborhood in Santiago on Monday and called for a big victory in the runoff that would force the left and right to swing into line behind her.

Matthei, 60, a former labor minister, says Chile must continue business-friendly policies she credits for fast growth and low unemployment during Pinera's term.

Matthei voted for eight more years of Pinochet in power in a 1988 referendum and now opposes changing the Pinochet-era constitution. She also says that economic growth, not raising taxes, must fund new spending.

Chile is the world's No. 1 copper producer, and its fast-growing economy, low unemployment and solid democracy are the envy of Latin America.

But Chile's schools are failing to prepare enough of its citizens for good jobs. Pinochet pushed privatization and ended central control and funding of public education, which suffered even as a voucher system directed billions of tax dollars to private high schools.

In an ominous sign for Bachelet, a group of students briefly occupied her campaign headquarters Sunday, saying no government is capable of generating the required change.

"Bachelet is likely to win," said Guillermo Holzman, a political science professor at the University of Valparaiso. "But it's going to get really hard for her when she becomes president."


Michael Warren reported from Buenos Aires, Argentina. Associated Press writer Eva Vergara in Santiago contributed to this report.


Luis Andres Henao on Twitter:

Michael Warren on Twitter: