Former Indiana Mayor Pete Buttigieg greets supporters on Feb. 28. Photo: Win McNamee/Getty Images

The first southern U.S. state is picking a 2020 Democratic presidential nominee on Saturday, as South Carolina voters line up at polls open from 7 a.m. to 7 p.m. EST.

Why it matters, via Axios' Fadel Allassan: 61% of South Carolina's Democrats are black, and Saturday's primary is the first major test of African-American support for the candidates.

Pete Buttigieg attends a canvass kick-off event in Columbia, South Carolina on Feb. 29. Photo: Reuters/Eric Thayer
People walk past a polling station on Feb. 29 in Charleston, South Carolina. Photo: Spencer Platt/Getty Images
A woman checks in with a poll worker before joining other voters at Mary Ford Elementary School in North Charleston, South Carolina on Feb. 29. Photo: Joshua Lott/AFP via Getty Images
A campaign event for former Vice President Joe Biden at Wofford University on Feb. 28. Photo: Sean Rayford/Getty Images
A couple watch President Trump in an overflow lot during his Feb. 28 Keep America Great rally in North Charleston, South Carolina. Photo: Joshua Lott/AFP via Getty Images
A voter exits a polling station at Mary Ford Elementary School in North Charleston, South Carolina, on Feb. 29. Photo: Joshua Lott/AFP via Getty Images
Voters on Feb. 29 in Charleston, South Carolina. Photo: Spencer Platt/Getty Images
Voters on Feb. 29 in Columbia, South Carolina. Photo: Sean Rayford/Getty Images
A voter at the Charleston County Housing and Redevelopment Authority in Charleston, South Carolina on Feb. 29. Photo: Joshua Lott/AFP via Getty Images
Voters at the Charleston County Housing and Redevelopment Authority in Charleston, South Carolina on Feb. 29. Photo: Joshua Lott/AFP via Getty Images

Go deeper: Biden bets it all on South Carolina

Go deeper

Pence chief of staff Marc Short tests positive for coronavirus

Marc Short with Katie Miller, Vice President Pence's communications director, in March. Photo: Doug Mills/The New York Times via Reuters

Marc Short, Vice President Mike Pence’s chief of staff, tested positive for the coronavirus Saturday and is quarantining, according to a White House statement.

Why it matters: Short is Pence's closest aide, and was one of the most powerful forces on the White House coronavirus task force.

Updated 51 mins ago - Politics & Policy

Coronavirus dashboard

Illustration: Aïda Amer/Axios

  1. Politics: Pence chief of staff Marc Short tests positive for coronavirus — COVID-19 looms over White House Halloween celebrations
  2. Health: Fauci says maybe we should mandate masks if people don't wear them — America was sick well before it ever got COVID-19
  3. World: Polish President Andrzej Duda tests positive for COVID-19.
2 hours ago - World

Opposition leader Leopoldo López flees Venezuela

Venezuelan opposition politician Leopoldo López outside the Spanish embassy in Caracas, in 2019. Photo: Juan Barreto/AFP via Getty Images

Leopoldo López, a former political prisoner and prominent Venezuelan opposition leader, has left the country, his Popular Will party confirmed in a statement Saturday.

Why it matters: He's been an influential force in the push to oust President Nicolás Maduro's regime and a mentor to opposition leader Juan Guaidó. He'd been in the Spanish ambassador's Caracas residence since escaping house arrest in April 2019 following a failed military uprising.