On Politics: A Busy Weekend in Iowa

At least four Democratic presidential candidates called on Walmart on Friday to stop selling guns after the mass shooting at one of the company’s stores in El Paso last weekend.

Nearly the entire field descended on Northern Iowa on Friday night for the Wing Ding dinner, an annual event that has long served as an early testing ground for Democratic presidential aspirants. In speech after speech, the candidates assailed President Trump and Republicans for their lack of action on gun control and abetting white supremacy.

Violence by white extremists is an undeniable and intensifying problem. But the question of how the government should attack domestic extremism, especially white supremacists, remains as politically fraught as ever, with skepticism rooted in the White House.

Mr. Biden raised eyebrows on Thursday during a speech in Iowa when he said that “poor kids are just as bright and just as talented as white kids,” an apparent gaffe for a Democratic presidential candidate whose record on race has come under intense scrutiny during the primary.

For years Mr. Trump has brashly — and baselessly — promoted suspicion as fact. On Saturday he was at it again, tweeting unfounded conspiracy theories about how Jeffrey Epstein, the financier accused of sex trafficking, died in a federal jail.