President Donald Trump granted Attorney General William Barr broad new powers to investigate the origins and conduct of special counsel Robert Mueller’s probe into Russian election interference and the Trump campaign.

“Today, at the request and recommendation of the Attorney General of the United States, President Donald J. Trump directed the intelligence community to quickly and fully cooperate with the Attorney General’s investigation into surveillance activities during the 2016 Presidential election,” Trump tweeted Thursday night.

The memo also gives Barr unique authority to declassify records from the country’s 16 intelligence agencies, including the Central Intelligence Agency and the National Security Agency — incredibly broad power that usually rests with the president, not the attorney general.

“Today’s action will help ensure that all Americans learn the truth about the events that occurred, and the actions that were taken, during the last Presidential election and will restore confidence in our public institutions,” Trump added.

The move effectively secures Barr at the head of an investigation into what Trump and his allies have said was an illegal — and even treasonous — investigation into the president and his campaign by partisans within the Federal Bureau of Investigation, the Justice Department, and the Intelligence Community.

It also raises the specter of investigations driven by politics rather than the law. Barr has repeatedly used the office of attorney general to give the president political cover: he notably misrepresented the findings of the Mueller report to further the president’s false claim that the report exonerated him.

Trump surrogate Corey Lewandowski on Thursday previewed a new angle of attack the administration is apparently pursuing. He claimed without evidence that former Vice President Joe Biden — a leading Democratic contender to challenge Trump in 2020 — is behind what he said was an illegal investigation into the president. Lewandowski went on to name a laundry list of former Obama administration officials he said are likely to stand trial, several of whom have served under both Democratic and Republican presidents.

“And we can’t wait,” Lewandowski said.

In addition to a partisan use of public office, Barr’s investigation is plainly redundant: There are already several investigations into the Russia probe, including by John Durham, the U.S. attorney in Connecticut; John Huber, the U.S. attorney in Utah; and Justice Department Inspector General Michael Horowitz. The attorney general appears to have positioned himself at the head of those inquiries.

Barr — an enthusiastic centurion for Trump — was appointed after his predecessor, former Attorney General Jeff Sessions, displeased the president by recusing himself from overseeing the Russia investigation. After its conclusion, Mueller and members of his team privately complained that Barr mischaracterized their findings when he summarized the report in a public letter that said the president was cleared of wrongdoing.

The report explicitly says the president is not cleared of allegations of obstruction of justice, and the special counsel’s office left it up to Congress to pursue the charges further. More recently, Barr said, again without evidence, that the Obama administration “spied” on the Trump campaign — a remarkable comment coming from a sitting attorney general.

Trump has repeatedly claimed, without evidence, that former President Barack Obama “tapped” his Trump Tower campaign headquarters in 2016. Many Republicans have also seized on anti-Trump text messages exchanged by two early members of the FBI team that began the investigation into Russian election interference, Peter Strzok and Lisa Page.

Other Trump partisans have claimed the FBI inappropriately relied on a dossier of private opposition research compiled by former British intelligence officer Christopher Steele, which was partially funded by the law firm for Hillary Clinton’s presidential campaign. That dossier formed part of the evidence the FBI submitted when requesting a Foreign Intelligence Surveillance Act warrant on Trump campaign foreign policy advisor George Papadopoulos.

Those claims have largely fallen apart under scrutiny. But calls by congressional Republicans and conservative media outlets to pursue a broad investigation into the FBI, the Justice Department, and the Intelligence community have grown louder by the day since Mueller and his team published their final report, which did not establish that the Trump campaign criminally conspired with Russia to tamper with the election, but did find ample evidence that the president and his subordinates may have obstructed justice.

“As I have long been saying, and has now been proven out, this is a Witch Hunt against the Republican Party and myself, and it was the other side that caused the problem, not us!” Trump tweeted Wednesday.

Trump and his allies in Congress have repeatedly called for congressional Democrats to stop their investigations into the president, his campaign, and Russian election interference — to “go back to work and legislate,” as Trump said yesterday.

With Barr as the sole head of an investigation with sweeping powers of discovery and disclosure, the back-and-forth over 2016 is still unfolding — and now puts the president’s closest allies in a unique position to target Democratic candidates hoping to challenge Trump in 2020.