Sunday's presidential runoff in Costa Rica pits a conservative evangelical singer against a former cabinet minister from the ruling center-left Citizens’ Action Party, and has been fought largely over gay marriage.

Why it matters: Costa Rica is Latin America's oldest democracy, but crime, high unemployment and corruption allegations have jolted the country's historically stable politics. The gay marriage debate has added fuel to the fire. Per the Economist, "dissatisfaction is showing up as support for unconventional candidates."

• Fabricio Alvarado Munoz, the 43-year-old singer and former TV host, surged to a first place finish in the first round on February 4, after denouncing a court ruling calling for same sex marriage to be legalized.
• Carlos Alvarado Quesada, 38, has slammed his opponent's "homophobic positions." He has also trailed him consistently in the polls — though some show a close race and, per Reuters, "polls have a patchy record in Costa Rica."