"I have an Article 2, where I have the right to do whatever I want as president." – President Donald Trump, July 23, 2019

WASHINGTON – The Constitution of the United States of America does, indeed, have an Article II. It's the president's job description, circa 1787, and it gives him sweeping powers.

But not whatever he wants. In fact, it defines something he doesn't want: the terms for his impeachment, conviction and removal from office.

As House Democrats prepare their case for impeachment, attention increasingly will focus on the nation's founding document, which outlines the unique roles of Congress, the president and the federal courts.

And so, the question: Has Trump violated the Constitution?

And does that justify ending his presidency?

Not if his lawyers have anything to say about it. In federal appeals court in New York Wednesday, they argued that Trump could shoot someone on Fifth Avenue without criminal consequence because he is immune from prosecution while in office.

Immunity:President Donald Trump could shoot someone in public and escape prosecution, his lawyer tells federal court

Article II spells out the president's oath of office, which concludes with his duty to "preserve, protect and defend the Constitution of the United States." It also specifies that he "shall take care that the laws be faithfully executed."

Then it sets out the potential reasons for his removal: if he is impeached by the House, and convicted by the Senate of "treason, bribery, or other high crimes and misdemeanors."

Throughout Trump's presidency, investigations into Russia's efforts to influence the 2016 election and other matters relating to his business dealings have made impeachment a possibility. This summer's revelations that Trump asked Ukraine's president to investigate past and future political opponents made it probable, if not inevitable.

Ukraine:Trump's conspiracy theories thrive in Ukraine, where a young democracy battles corruption and distrust

"We believe the acts revealed publicly over the past several weeks are fundamentally incompatible with the president’s oath of office, his duties as commander in chief, and his constitutional obligation to 'take care that the laws be faithfully executed,'" 16 conservative and libertarian lawyers wrote earlier this month under the imprimatur of the group Checks and Balances.

University of Southern California law professor Orin Kerr, a former Justice Department official and a member of the group, puts it simply: "He’s taking care of himself, not taking care of the country."

But Georgetown University law professor Randy Barnett says Trump's accusers "have been alleging impeachable offenses since before President Trump took the oath of office."

"They have their conclusion in hand," Barnett says, "and now they’re just trying to fill out the bill of particulars.”

'Very good to Ukraine'

"When the president does it, that means that it is not illegal." – Former President Richard Nixon, May 19, 1977

What Trump did on July 25 was ask Ukraine's new president, Volodymyr Zelensky, to investigate the Democrats' leading presidential candidate at the time, Joe Biden, and his son Hunter. Trump also asked indirectly for a probe of emails stolen from the Democratic National Committee in 2016.

In the same conversation, the president noted that "the United States has been very, very good to Ukraine. I wouldn’t say that it’s reciprocal, necessarily."

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Jonathan Adler, a Case Western Reserve University law professor and a member of Checks and Balances, says “the persistent efforts to use foreign policy as a means of advancing or protecting his own political interests" conflicts with the presidential oath.

"'High crimes and misdemeanors' has never been understood to be limited to or consigned to things that are crimes in the narrow legal sense," Adler says. "They encompass actions that are violative of the solemn obligations that a public official takes."

President's piggy bank?

"I’m taking money from here and there and there and there.... We have all these different sources coming from all over the place because they won’t approve it." – President Trump, July 23, 2019

The president was referring at the time to financing his long-sought wall along the border with Mexico – spending power that the Constitution largely reserves for Congress. He has moved money from the Pentagon and other agencies to the Department of Homeland Security for that purpose.

That's another constitutional violation, says George Mason University law professor Ilya Somin, another Checks and Balances member. Trump, he says, is using the federal budget as "his personal piggy bank" – going so far as to withhold nearly $400 million in military aid to Ukraine previously appropriated by Congress.

“This is a big deal, frankly a bigger deal than some of the stuff that’s more in the headlines,” Somin says, calling it "an unconstitutional usurpation of Congress' power of the purse."

'Walking, talking violation'

"You people with this phony Emoluments Clause." – President Trump, Oct. 21, 2019

That would be Article I, Section 9, Clause 8 of the Constitution, which bars federal officeholders from accepting gifts from foreign governments. It is derived from the Latin word "emolumentum," meaning "profit" or "gain." And another prohibition in Article II prohibits the president from receiving domestic emoluments.

Trump's continuing ownership of hotels and restaurants, such as Trump International Hotel in Washington, D.C., where foreign leaders often stay, has spurred three federal lawsuits. Two courts of appeals are scheduled to hold oral arguments in December.

Deepak Gupta, an attorney litigating two of the lawsuits, says Trump's presidency is "a walking, talking Emoluments Clause violation" because Trump never divested himself of his real estate holdings.

"The Framers were obsessed with the possibility of corruption," Gupta says.

Rather than retreat in the face of the Emoluments Clause, Trump last week sought to double down by scheduling the upcoming Group of 7 conference of Western global economic powers at Trump National Doral, his Miami-area resort. Only in the face of withering criticism from Republicans as well as Democrats did he reluctantly back down.

Pledging obstruction

"President Trump and his administration cannot participate in your partisan and unconstitutional inquiry under these circumstances." – Pat Cipollone, counsel to the president, Oct. 8, 2019

An eight-page letter from the White House counsel earlier this month basically declared war on House Democrats' impeachment inquiry. The president, Pat Cipollone said, won't cooperate.

If that constitutes obstruction of justice, critics say, it wouldn't be the first time. They cite special counsel Robert Mueller's report on Russian interference in the 2016 election, which outlined Trump's efforts to withhold evidence and influence aides' testimony.

“The Article II power does not extend to telling subordinates and others to lie about what occurred,” Adler said, referring to the president's attempt to have former White House counsel Don McGahn say that Trump did not seek to have Mueller fired.

But others defend the president's resistance. In testimony to the House Judiciary Committee in July, Chapman University law professor John Eastman said Mueller "was not fired, and even if he had been, the investigation would not have been stopped."

"If that is obstruction, it pales in comparison to recent examples of real obstruction that have gone largely unremarked," Eastman said.

'Nobody really knows'

"An impeachable offense is whatever a majority of the House of Representatives considers it to be at a given moment in history." – Former President Gerald Ford, April 15, 1970

Alexander Hamiton wrote extensively on impeachment in the Federalist Papers, but the Constitution gives it only six brief mentions. The references leave plenty of leeway.

"The Constitution gets violated all the time," Barnett says. "That doesn’t make the violation of the Constitution a high crime or misdemeanor."

Some don't see the need for specificity. “It’s about abusing the office, not about violating a technical provision of a particular clause," Kerr says.

While Trump's opponents see obvious cause for impeachment and his defenders do not, others simply see a reason for disagreement. University of Texas law professor Sanford Levinson wrote in the journal Democracy in August that the problem is the Constitution itself.

The impeachment clause "has been captured by lawyers who simply shout at one another about what in fact constitutes such a 'high crime or misdemeanor,'" Levinson wrote. "The correct answer is that nobody really knows."