WASHINGTON — The Senate Judiciary Committee this week expanded its investigation into Russian election meddling, announcing that it would look at whether President Trump obstructed justice by trying to quash the F.B.I. inquiry into his former national security adviser.

Here is a snapshot of where three of the active congressional inquiries stand.

Senate Judiciary Committee: Did Mr. Trump, and Loretta Lynch, act improperly?

While the Senate and House intelligence committees have taken the lead investigating Russian intrusion in the 2016 election, the Judiciary Committee has more quietly been pursuing its own inquiry.

Senator Charles E. Grassley, Republican of Iowa and the committee chairman, said on Wednesday that the panel, which oversees the Justice Department, would investigate attempts to influence F.B.I. investigations.

Attempts — plural.

At the urging of Senator Dianne Feinstein of California, the committee’s ranking Democrat, Mr. Grassley said its investigation should include the removal of James B. Comey as F.B.I. director, the Russia investigation and — in light of Mr. Comey’s testimony last week that Ms. Lynch, the former attorney general, had tried to influence him — the investigation into Hillary Clinton’s use of a private email server.