I admired Rudolph W. Giuliani when he was mayor of New York. The think tank for which I then worked, the Manhattan Institute, was close to the mayor’s team, and I recall fondly the times I spoke with him and his staff about how to make the city a better place to live. His policies changed New York from a crime- and murder-riven city into what it is today: one of the safest large cities in the United States. He earned America’s respect on 9/11 with his calm and courageous leadership in the face of civic and national tragedy. He was, for me and many others, a hero.

Sadly, that man no longer seems to exist. Instead, we have a hack partisan, now serving as President Trump’s lawyer, who says anything and does anything to advance his client’s (and friend’s) interests. His behavior Thursday while discussing the reported dealings between the administration and recently elected Ukrainian President Volodymyr Zelensky further suggests he is not able to control his impulses and that he cannot withstand the pressures the position he has taken place him in. It’s time for Giuliani to leave public life.

To understand the full extent of Giuliani’s fall, one has to understand some important context about politics in the former Soviet republic. Russia has tried for decades to bring Ukraine back into its orbit. It first sought to influence Ukrainian elections, with pro-Russian candidates popular among Ukrainians living in the east. But after popular discontent with pro-Russian president Viktor Yanukovych led to his ouster in 2014, Russia turned up the heat. It annexed the Ukrainian territory of Crimea and militarily aided rebels in Ukraine’s Donetsk and Luhansk regions. The two countries have informally been at war ever since.

Ukraine cannot supply its own military needs against Russian pressure, so it has long sought to obtain U.S. and Western military assistance. Trump had authorized such aid earlier in his tenure. Where Trump and Giuliani’s current troubles stem from is how they allegedly acted on a $250 million installment of that aid that was due to be provided this summer.

Reports suggest that Trump pressured Zelensky to investigate former vice president Joe Biden’s son, Hunter, as a condition for U.S. release of the funds. Hunter Biden had business dealings in the Ukraine earlier this decade, and the New York Times reported this year that Joe Biden, as vice president, had traveled to Ukraine and threatened to have the United States withhold $1 billion in loan guarantees to the country unless it dismissed its top prosecutor, Viktor Shokin, who had investigated a company for which Hunter Biden served as a board member. Joe Biden’s demand was part of a larger effort by the United States and other Western allies, including the International Monetary Fund and the World Bank, to promote reform in the country against corruption, which Shokin had allegedly turned a blind eye to. The current prosecutor general in Ukraine said he had no evidence that either Biden committed any wrongdoing. But that hasn’t kept Trump and Giuliani from arguing that there should be a Biden investigation.

Trump’s alleged threat to withhold funds is especially problematic because it is part of a disturbing trend. There is substantial evidence that he was open to obtaining opposition research against Hillary Clinton from the Russian government during the 2016 election. Earlier this year, he publicly said he would consider taking opposition research from a foreign government. Despite subsequently walking back that statement, it’s clear that Trump seems blind to the bind he would place the United States in if his personal political gain were advanced with information obtained through direct interactions with other countries.

There is no evidence Trump has tried or will try to help another country prevail over U.S. interests. But if he did place personal interests first, he would compromise the public good to pursue his private good. Such a revelation would indeed harm the president.

But Giuliani is even more harmed by his purported behavior in this affair. He repeatedly pushed for Ukraine to investigate Biden in the media and in private meetings with Ukrainian officials. This alone is improper; he is Trump’s lawyer, not a government official, and doing so complicates U.S. diplomacy with Ukraine as their officials do not know who is speaking for the president.

Giuliani’s erratic behavior Thursday night, especially during an interview with CNN host Chris Cuomo is also alarming. Giuliani first denied he asked Ukrainian officials to investigate Biden only to reverse himself 30 seconds later. He then took to Twitter to say that Trump asking Zelensky to investigate Joe Biden was completely appropriate, which the White House denies ever happened.

Giuliani’s decline has not yet reached the madness of King Lear, but it is even more distressing to watch because of the noble heights from which he has fallen. We still have yet to see how this affair will affect the president. But in any case, Giuliani has proved that he’s incapable of serving the president or the country’s interests. It’s time for him to step aside.

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