FILE - In this June 21, 2017, file photo, special counsel Robert Mueller departs after a closed-door meeting with members of the Senate Judiciary Committee about Russian meddling in the election and possible connection to the Trump campaign, at the Capitol in Washington. As Congress returns to Washington, a web of President Donald Trump's family and associates will be in the crosshairs of committees investigating whether his campaign colluded with Russia last year, as well as of the high-wattage legal team assembled by Mueller. (AP Photo/J. Scott Applewhite, File)
FILE - In this June 21, 2017, file photo, special counsel Robert Mueller departs after a closed-door meeting with members of the Senate Judiciary Committee about Russian meddling in the election and possible connection to the Trump campaign, at the Capitol in Washington. As Congress returns to Washington, a web of President Donald Trump's family and associates will be in the crosshairs of committees investigating whether his campaign colluded with Russia last year, as well as of the high-wattage legal team assembled by Mueller. (AP Photo/J. Scott Applewhite, File) Credit: J. Scott Applewhite

Washington — As Congress returns from recess, President Donald Trump’s family and associates will be back in the crosshairs of congressional committees investigating whether his campaign colluded with Russia, as well as of the high-wattage legal team assembled by special counsel Robert Mueller.

Some of the attention will be focused squarely on the president’s eldest son, Donald Trump Jr., who will meet privately in the coming weeks with staffers on the Senate judiciary and intelligence committees. A meeting Trump Jr. convened with a Russian lawyer and others in the midst of the campaign has already been the subject of testimony before a grand jury that Mueller is using as part of his investigation, The Associated Press has learned.

The expected crush of interviews, subpoenas and testimony this fall underscores both the broad scope of the Russia probes and the certainty that they will shadow Trump’s presidency for months or even years. Even if Trump and his associates ultimately are cleared, some White House advisers worry about the president’s anger over the investigations and the likelihood that he will continue to weigh in publicly in ways that only further distract from his agenda.

The president’s own legal exposure remains uncertain. He’s denied coordinating with Russia during the election or having any nefarious financial ties to Moscow.

But Trump’s legal team, anticipating Mueller’s interest in probing Trump’s firing of FBI Director James Comey, is developing arguments to protect him against any obstruction of justice allegations, including constitutional defenses and a contention that his actions crossed no legal lines.

In a preview of those arguments, Trump attorney Jay Sekulow said constitutional powers authorize the president to fire subordinates who serve at his pleasure.

“The whole idea of an obstruction allegation here, or obstruction of justice charge, is contrary to the Constitution,” Sekulow said.

The simultaneous investigations by Mueller and three congressional committees have drawn in some of Washington’s legal heavy hitters. Mueller’s 16-lawyer team is comprised of seasoned prosecutors with significant experience fighting fraudsters, mobsters and terrorists and with building cases against high-level targets by eliciting cooperation from more peripheral subjects. And more than a dozen Washington law firms have lawyers representing players in the investigation.

Most participants are gearing up for a long haul. Rep. Adam Schiff, of California, the top Democrat on the House intelligence committee, said his panel has a “tremendous number of witnesses to get through” in the preparation of a public report.

“We feel a sense of urgency, but we also know it has to be thorough, or it won’t be of much value,” Schiff said.

The coming months may put a new focus on lesser-known players in Trump’s orbit, though familiar names also will continue to face scrutiny.