Bill Weld steps up attack on Trump: Former Massachusetts Gov. Bill Weld — President Donald Trump’s lone Republican primary challenger — has ramped up his verbal assault on Trump.

“I celebrate that America has always been a melting pot,” said Weld at an event earlier this week, according to an ABC News report. “It seems he would prefer an Aryan nation.”

When asked to explain what specifically he meant by “Aryan nation,” Weld told ABC that he believes the president “would prefer a nation with no immigrants.” The long-shot candidate also said he knows that sounds strong, but Trump is “interested in bloodlines.”

“It’s not just that I’m feeling more like going on the attack. It’s also that the president is moving to a deeper level of irresponsibility,” Weld added. Trump often has denied accusations that he’s racist, maintaining that he is the “least racist person” reporters “have ever interviewed.”

Biden faces opposition-research effort: Republican operatives have begun a “vast, coordinated opposition-research effort” aimed at derailing former Vice President Joe Biden in the Democratic presidential primary or at least making sure he hobbles into the general election, says a Vanity Fair report.

“There’s a lot of material on Biden,” one unnamed GOP strategist involved in the takedown attempt told the publication. “It’s sort of a gold mine of content.” The effort comes as Biden looks like the biggest threat to Trump in the general election, with the old-school Labor Democrat able to win votes in the industrial heartland, the report adds.

North Dakota firm reportedly gets presidential boost: Trump has personally and repeatedly urged the head of the U.S. Army Corps of Engineers to award a border-wall contract to a North Dakota construction firm whose top executive is a Republican donor and frequent guest on Fox News, according to a Washington Post report citing four unnamed administration officials.

Trump has aggressively pushed Dickinson, N.D.-based Fisher Industries, helmed by Tommy Fisher, to do work at the U.S.-Mexico border, and the backing of a specific company to do wall work has alarmed military commanders and Homeland Security officials, the report said.

Related:Here are the companies poised to profit from the Trump border wall

Republican campaigns spend big at Trump properties: GOP candidates and campaign committees have spent more than $4 million at hotel, golf and vineyard properties that bear Trump’s name since he was inaugurated in 2017, says a Hill report based on a review of disclosures made over the last two years.

More than three dozen members of Congress have held fundraisers or spent the night at Trump properties, according to the Hill. Trump’s own campaign has paid his businesses nearly $1.5 million over that span, and the Republican National Committee has spent more than $1.1 million at Trump-branded properties.

There is nothing in the Constitution that bans a campaign from spending money at a candidate’s business, but watchdog groups view the behavior as corrupting, the report added.

Maryland and Washington, D.C., are suing Trump based on their view that he’s violating the anti-corruption provisions in the Constitution’s emoluments clauses.