The decision by the Republican-led Senate Intelligence Committee to subpoena Donald Trump Jr. has ignited a GOP civil war. Allies of the Trumps and several Republican senators — specifically, those up for re-election in 2020 or close to President Trump — are attacking the committee chairman, Sen. Richard Burr (R-N.C.), and pressuring others to do the same, The New York Times and The Washington Post report. The effort has borne some fruit.

Burr's committee, which has been discreetly investigating Russian election interference and how to prevent it for two years, issued the subpoena more than a week ago, after Trump Jr. refused to voluntarily come in for a second interview, the Post reports. But its existence wasn't public until Wednesday, a day after Senate Majority Leader Mitch McConnell (R-Ky.) gave a speech in which he declared "case closed" on the Russia investigation, and it caught the White House off guard.

The "extraordinary pressure campaign" by Trump's allies "is forcing the party's senators to choose between their loyalty to the Intelligence Committee and to the president's family as it attempts to quash any remaining investigations of the president," the Times reports. And if Trump Jr. defies the subpoena, Burr and McConnell will have to decide whether to allow votes to hold him in contempt. Trump Jr. is "said to be 'exasperated' by the subpoena," the Post reports, and several of his confidantes tell the Times he's "unlikely to appear in person" and might "invoke his Fifth Amendment rights in a written response."

The Senate Intelligence Committee is reportedly interested in asking Trump Jr. follow-up questions about the Trump Tower Moscow deal and the Trump Tower meeting he set up to get "dirt" on Hillary Clinton from the Russians. But despite the apparently coordinated outrage from Team Trump, "the subpoena appears to have been essentially routine," the Times reports. "As it completes its work, the committee is calling back key witnesses who spoke to staff members so senators can question them directly." Peter Weber