CARACAS, Venezuela — President Nicolás Maduro cast his vote Sunday for the powerful constitutional assembly he championed while foes boycotted the polls and accused the controversial leader of a power grab that would slam the brakes on democracy.

The beleaguered South American nation is electing members to the new assembly that would rewrite the country’s 1999 constitution and possibly create a single-party, authoritarian system.

Maduro's vision has drawn ire in Washington. Last week, the Trump administration imposed sanctions on 13 senior Venezuelan officials, and the White House and some congressman said stiffer sanctions could follow. Mexico said it would support U.S. sanctions, and the Organization of American States and the European Parliament have also expressed support for the opposition.

In Venezuela, opposition leaders refused to put up candidates, arguing the election has been structured to ensure that Maduro’s ruling socialist party dominates. Thus virtually all the more than 5,000 candidates for 545 assembly seats are Maduro supporters.

The opposition vowed to protest despite a ban on public gatherings issued by Maduro. In some parts of the capital, people took to the streets in protest against the vote, but they were soon repelled by security forces throwing tear gas.

Opinion polls indicated more than two-thirds of the nation opposed the president's efforts, and early voting at many polling places was light. The opposition says the government was so afraid of low turnout that it threatened to fire state workers who don’t vote and take away social benefits like subsidized food from recipients who stay away from the polls.

“I’m here because I’m hoping for housing,” admitted hairdresser Luisa Marquez, 46, as she waited in line to vote.

Maduro has struggled with a rapidly deteriorating economy and strengthening political opposition. Some voters said they believed the new assembly might improve life in Venezuela.

“I’m voting today because I want peace to be restored,” said seamstress Carmen Martinez, 44. But she said she was less certain the assembly will solve the nation's economic ills.

"I’m going to have hope, but I doubt this could solve that problem," she said.

Months of violence leading up to the vote showed little signs of ending, with media reporting that a leading assembly candidate and an opposition activist were killed before voting even began.

José Felix Pineda, a lawyer running in the election, was shot in his home Saturday night, a senior Venezuelan minister told the BBC. And Ricardo Campos, a youth secretary with the opposition Acción Democrática party, was shot dead during a protest, the head of the National Assembly said.

Maduro has denied links to violent paramilitaries that have run roughshod across the country, blaming the opposition for unrelenting violence that has left more than 100 people dead.

Maduro himself voted with little fanfare early in the morning.

“We’ve stoically withstood the terrorist, criminal violence,” Maduro said. “Hopefully the world will respectfully extend its arms toward our country.”

Contributing: John Bacon in McLean, Va.