Why it matters: The disputes raise several issues, including how far Congress’s subpoena power extends, what Mr. Trump can keep secret under executive privilege, and whether a president’s aides are “absolutely immune” from orders to appear before lawmakers.

Related: Michael Cohen, Mr. Trump’s former personal lawyer, told congressional investigators that his discussions with the president’s legal team about a potential pardon continued longer than previously known, newly released transcripts show.

Huawei is frozen out in tech war

Google, whose Android software powers Huawei’s smartphones, said on Monday that it would limit the services it provides the telecommunications giant, after a White House order last week restricted the Chinese company’s access to American technology.

The Commerce Department later announced that it would grant a 90-day reprieve for transactions necessary to maintain and support existing networks and cellphones.