Politics Jun 12

WASHINGTON, DC - JANUARY 25: Sen. Heidi Heitkamp (D-ND) speaks to the media about immigration, after attending a bipartisan meeting in Sen. Susan Collins office, on Capitol Hill January 25, 2018 in Washington, DC. (Photo by Mark Wilson/Getty Images)
What to watch in Tuesday’s primaries

The contests -- in Nevada, Maine, North Dakota, South Carolina and Virginia -- include key Senate seats held by vulnerable incumbents from both parties. Here's what to watch.