Bolivians headed to the polls on Sunday to vote in presidential and congressional elections that could spell the end of the Andean nation’s long-dominant leftist party and see a right-wing government elected for the first time in over two decades, Associated Press reported.

The election on Sunday is one of the most consequential for Bolivia in recent times — and one of the most unpredictable.

Even at this late stage, a remarkable 30% or so of voters remain undecided. Polls show the two leading right-wing candidates, multimillionaire business owner Samuel Doria Medina and former President Jorge Fernando “Tuto” Quiroga, locked in a virtual dead heat, according to Associated Press.