A look at how socialism is gaining ground inside the Democratic Party while turning off the independents Democrats need to win — a warning sign for the party heading into the midterms.

• Socialist candidates are winning Democratic primaries, and most Democrats now view socialism favorably.
• Independents strongly dislike socialism, so leaning left could cost Democrats swing voters.
• Democrats need to flip four Senate seats to take control, a steep climb.
• They first have to hold their own seats in Georgia, New Hampshire, and Michigan just to stay even.
• Their best pickup shots are Maine (against Susan Collins) and North Carolina, where they nominated the former governor.

Outlook: A big Michigan primary in the coming weeks will test whether the party's leftward shift helps or hurts its chances in November.