Mexicans began casting votes in Sunday’s elections amid signs they’re set to hand the presidency to a left-wing leader for the first time in decades, in a revolt against entrenched corruption, crime and poverty.

Andres Manuel Lopez Obrador appears headed for a landslide win that could also give him majorities in both houses of Congress — a prospect that’s adding to anxiety in Mexico’s business world and financial markets. Nine governors and almost 3,000 mayors and local legislators will also be chosen.

The biggest election in Mexican history got under way at 8 a.m. local time, though there were delays at some ballot stations. Polls are due to close at 6 p.m. and initial results are expected sometime after 8 p.m. The campaign has been marred by violence, with more than 120 politicians killed, including some 40 candidates. In a midday press conference, Lorenzo Cordova, head of the electoral regulator INE, said the indications were that voting was proceeding peacefully so far.

Lopez Obrador cast his ballot early Sunday in the capital, Mexico City. “Today, people are going to decide if they want more of the same or a real change,” he said.

Mexicans have many reasons to kick out their governing class. The country of 125 million has suffered a wave of violent crime, with homicides at record levels. Then there’s the $1.2 trillion economy, which has posted dismal growth rates by developing-nation standards. Almost half the population lives in poverty, a rate that’s changed little in a quarter-century. And the outgoing government has been caught up in a series of graft scandals.

“We need a complete transformation in Mexico,” said Sergio Oceransky, 45, at a polling station in central Mexico City. “We’re experiencing a tremendous political crisis that’s no longer sustainable.”

The 64-year-old Lopez Obrador, known as AMLO, promises to ramp up social programs and run a clean administration. His strong showing fits with a global trend of anti-establishment politics, from gains by parties of the left and right in Europe to Donald Trump’s presidency in the U.S. There are also regional echoes: Mexico is one of the few countries in Latin America that hasn’t had a leftist government in recent decades.

The candidate was a popular mayor of Mexico City last decade and has unsuccessfully run for the presidency twice since then. Lopez Obrador says he’ll govern as a pragmatist, and he’s promised not to nationalize companies or quit Nafta. But investors are worried that he’ll cancel private oil contracts, scrap a $13 billion Mexico City airport project that’s already under way, and rack up debts. The peso has slid about 10 percent since mid-April.

Read more about Mexico’s populist presidential candidate here

Lopez Obrador says he can fund his programs by eliminating corruption and cutting the salaries of high-paid bureaucrats, and won’t need to run bigger deficits. Economists are skeptical about the claim.

His two main rivals for the presidency are both more business friendly -– and represent the only two parties to have ruled Mexico in almost a century.

Ricardo Anaya, a brash 39-year-old, cobbled together a coalition of the right and center-left. His pledge of a drastic crackdown on corruption has been undermined by his ties with past governments seen as corrupt themselves.

Jose Antonio Meade was finance minister under the outgoing –- and deeply unpopular –- administration of the Institutional Revolutionary Party or PRI. It’s headed by President Enrique Pena Nieto, who was hailed as an economic reformer early in his term, and ended it with the lowest approval ratings in the history of the presidency.

He’ll remain in office until December whatever today’s outcome, because Mexico has a five-month gap between elections and inauguration.

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.