You know it’s a bad day for the White House when the president’s former campaign chairman is charged with money laundering, tax fraud, making false statements and failing to register as a foreign agent — and that is only the second most damaging story of the morning.

Early Monday, Paul Manafort, who led Donald Trump’s campaign during several crucial months in 2016, and a longtime Manafort associate, Rick Gates, who was also a Trump campaign official, surrendered to federal authorities after being named in an indictment obtained by Robert Mueller III, who was appointed as special counsel in May to investigate connections between the Trump campaign and the Russian government.

These are the sorts of people Mr. Trump has regularly chosen to associate with. And given Monday’s developments, they’re not the only ones who should be afraid of being ensnared in Mr. Mueller’s spreading net.

Both men pleaded not guilty. The crimes they are charged with are very serious — money laundering alone carries a sentence of up to 20 years in prison — but on their own they suggest no immediate link to the original subject of Mr. Mueller’s investigation: possible collusion between the Trump campaign and the Russian government to help swing the election to Mr. Trump, and any subsequent cover-up of that collusion.