Attorney General Jeff Sessions resigned today as the country's chief law enforcement officer after enduring more than a year of blistering and personal attacks from President Donald Trump over his recusal from the Russia investigation.(AP Photo/Pablo Martinez Monsivais)

WASHINGTON (AP) — Attorney General Jeff Sessions resigned today as the country’s chief law enforcement officer after enduring more than a year of blistering and personal attacks over his recusal from the Russia investigation.

Sessions announced his resignation in a letter to President Donald Trump. He said the resignation came at “your request.”

Trump announced in a separate tweet that he was naming Sessions’ chief of staff Matthew Whitaker, a former United States attorney from Iowa, as acting attorney general.

The resignation was the culmination of a toxic relationship that frayed just weeks into the attorney general’s tumultuous tenure, when he stepped aside from the investigation into potential coordination between the president’s campaign and Russia.

Trump blamed the decision for opening the door to the appointment of special counsel Robert Mueller, who took over the Russia investigation and began examining whether Trump’s hectoring of Sessions was part of a broader effort to obstruct justice and stymie the probe.

The top Democrat on the House Judiciary Committee says he wants “answers immediately.”

Jerry Nadler is in line to become the chairman of the Judiciary panel when Democrats take control of the House in January. He tweeted that “we will be holding people accountable.”

Nadler says he wants to know why Trump is making the change and “who has authority over Special Counsel Mueller’s investigation?”

Senate Minority Leader Chuck Schumer says it is “paramount” that Mueller’s investigation be protected.

Schumer says he finds the timing of Sessions’ departure “very suspect.” The New York Democrat says it would spark a “constitutional crisis” if Trump forced out Sessions as a “prelude” to ending or limiting Mueller’s investigation.