The president has grounded a military jet set for use by the Democratic House speaker, yanked a security clearance from a former CIA director critical of him, threatened to withhold disaster aid from states led by Democrats, pushed to reopen a criminal investigation targeting Hillary Clinton and publicly called for federal action to punish technology and media companies he views as biased against him.

Taken as a whole, Trump’s use of political power to pursue personal vendettas is unprecedented in modern history, said Matthew Dallek, a political historian who teaches at George Washington University.

“It’s both a sign of deep insecurity on his part and also just a litany of abuse of power,” he said. “I don’t think anyone really has done it as consistently or as viciously as Trump has. No one has used the power of the bully pulpit in such a public way.”

After Trump publicly and privately campaigned for the Israeli government to block Reps. Ilhan Omar (D-Minn.) and Rashida Tlaib (D-Mich.) from visiting Israel this weekend, Prime Minister Benjamin Netanyahu reversed himself on Thursday and announced the blockade due to the lawmakers’ support for a movement that calls for boycotting Israeli goods and services to protest Israeli treatment of Palestinians.