BOGOTA, Colombia

Bolivians headed to the polls on Sunday for an election that could end the 20-year reign of the governing leftist MAS party.

The South American nation, with a population of about 12.5 million, has nearly 7.9 million registered voters. They will cast ballots for the next president, vice president, 36 senators, and 130 deputies.

The elections are happening amid deep political polarization. The left is fractured by a feud between incumbent President Luis Arce and former President Evo Morales, who despite having been allies, have been fighting for control of the ruling party.

According to recent polls, two right-wing candidates are positioned to win – Samuel Doria Medina of the National Unity Front and Jorge “Tuto” Quiroga of the Freedom and Democracy party. On the left, only Andronico Rodriguez has a chance, potentially advancing due to the 30% of undecided, blank, and null votes.

Both Quiroga and Doria Medina have run for president and lost three times before. Quiroga previously served as president from 2001 to 2002, completing the final year of former military dictator Hugo Banzer's term after Banzer resigned due to lung cancer.

Both opposition leaders have pledged to dismantle the state-led economic model implemented by the MAS.

Whoever wins will inherit an escalating economic crisis. The country is grappling with a shortage of US dollars, a sustained rise in living costs, and prolonged periods of diesel and gasoline scarcity, all driven by a reliance on imports.

Polls suggest the race is close and may not produce a clear winner in the first round. If no candidate secures more than 50% of the vote, or at least 40% with a 10-point lead, an unprecedented second round will be held on Oct. 19.

Polls opened at 8:00 a.m. (1200GMT) and will close at 4:00 p.m. local time, with initial results expected after 9 p.m. Full official results are due within seven days.