“I can do stuff that’s unbelievable,” Trump told supporters. He also said large companies that once would not take his calls now “kiss my ass.”

The remarks come less than two weeks before the Nov. 3 midterm elections, as Trump campaigns for Republican candidates and his administration takes actions that have tested longstanding limits and customs of the presidency.

Those actions include a Justice Department raid on a congresswoman’s home, the removal of trees in Washington, D.C., over a judge’s wishes, and agreements with Russia that run counter to sanctions enacted by Congress. Earlier this month, the administration also announced investigations into nine universities, including Harvard and Yale, alleging they brought in international students to undercut U.S. wages.

The disputes reflect a broader shift in power toward the executive branch, said Tevi Troy, a presidential historian who served in the George W. Bush White House. Congress, he said, has ceded authority over roughly the past 25 years, leaving presidents more room to act without lawmakers.

Troy said Trump’s approach is distinctive because he uses executive power not only to overcome legislative gridlock but also to confront political and cultural opponents. He described Trump as a “unilateralist,” saying the president’s defining approach is a willingness to act alone.

Republican strategist Ryan Williams, who helped lead Mitt Romney’s presidential campaign, said Trump has made clear he intends to pursue his priorities without being constrained by tradition or advisers urging restraint.

The central question, according to the account of Trump’s second-term actions, is increasingly how far the president can go and what institutions, if any, will hold him back. Courts and Congress can serve as checks, but disputes over executive authority often unfold through litigation and political battles over the reach of federal agencies.

Frank Sesno, a former CNN Washington bureau chief who teaches media and public affairs at George Washington University, said the administration could use tools including investigations, contracts and security-clearance decisions against people or organizations whose views it opposes. He called those executive-branch powers “awesome weapons.”

Presidents before Trump have also challenged the boundaries of their office. George W. Bush used signing statements to contest or reinterpret parts of laws passed by Congress, while Barack Obama publicly defended using executive action when lawmakers did not act. The difference, critics and historians say, lies in the breadth and targets of Trump’s current efforts.

For voters heading to the polls, the stakes reach beyond individual disputes: the balance between the presidency, Congress and the courts shapes how federal policy is made and how much protection remains for institutions and people who challenge the administration.