US primaries test Democrats' leftward surge

Democratic voters across several US states were voting Tuesday in primaries that could show whether the party's anti-establishment left can extend recent wins into races that may matter for control of Congress in November.

The most consequential contest is in Minnesota, where leftist Lieutenant Governor Peggy Flanagan faces moderate congresswoman Angie Craig for the Democratic nomination to replace retiring Senator Tina Smith. Flanagan is backed by Smith and left-wing senators Bernie Sanders and Elizabeth Warren, while Craig is supported by Democrats who argue she is the safer general-election candidate.

Flanagan has criticised Craig over her support for the Republican-backed Laken Riley Act on immigration. Craig has emphasised electability and later expressed regret over her vote.

Wisconsin offers another test in a governor's race. Democratic socialist Francesca Hong is widely seen as the frontrunner for the nomination, while Milwaukee County Executive David Crowley has become the main moderate alternative.

The contests follow Abdul El-Sayed's narrow victory last week over establishment-backed Haley Stevens in Michigan's Democratic Senate primary, a result that energized progressives but also underlined the difficulty of polling low-turnout races.

Republicans also face a loyalty test in South Carolina. Senator Darline Graham, appointed after the death of her brother Lindsey Graham, is seeking the Republican nomination for a full term with President Donald Trump's endorsement. Her rivals include congressmen Ralph Norman and Russell Fry and former governor Mark Sanford. A runoff later this month is considered likely if no candidate reaches 50 percent.