Not for the first time, President Trump has revealed the fragility of this country’s democratic system. Three years into his presidency, the evidence of a weakened system is all around. It has happened in plain sight.

The latest involves the president and Ukraine. Based on what has so far been reported, the president asked, encouraged or demanded that the leader of a foreign government undertake an investigation designed to produce information that could damage a potential 2020 campaign rival.

Whether this also involved a quid pro quo is in question. The full story is not yet known. The biggest reason the details are not known is because Trump’s White House and the Justice Department, which is supposed to operate independently, have so far prevented Congress from obtaining the information that could help reveal what is missing.

Over the past few days, reporting first by The Washington Post and later by other organizations has provided the outline of a disturbing story. Unless there is substantial countering information, it portrays a president abusing his powers purely for political gain.

The outlines are these: According to multiple reports, on July 25, the president spoke on the phone with newly elected Ukrainian President Volodymyr Zelensky. In that conversation, he pressed the Ukrainian leader to reopen an investigation into a company that at one time had Hunter Biden, the son of Democratic presidential candidate and former vice president Joe Biden, on its board.

National Security reporter Shane Harris explains what we know know about President Trump's phone call with the Ukrainian president. (Zach Purser Brown/The Washington Post)

Shortly after that phone call, Rudolph W. Giuliani, the former New York mayor and Trump’s personal lawyer, met in Spain with an adviser to Zelensky. Giuliani further pressed the Ukrainian government to pursue the investigation involving Biden’s son, as well as one about alleged Democratic involvement with Ukrainians affecting Paul Manafort, Trump’s former campaign chairman who is in prison.

Meanwhile, during this period, $250 million in military assistance for Ukraine, money appropriated by Congress, was, for a time, held up. Was that directly connected to Trump’s efforts to pressure the Ukrainians? That question also remains unanswered.

The contents of the Trump phone call prompted someone in the government to file a whistleblower complaint, an unprecedented grievance aimed at the president. The inspector general for the intelligence community found the whistleblower’s charge credible and urgent, in which case the information should have been relayed to Congress. That hasn’t happened because the White House and Justice Department are fighting it.

That is roughly where things stand as of the weekend. Congress will fight for the information, and a lengthy court battle could ensue. That would be par for the course, as Trump’s White House and Justice Department have consistently and persistently resisted any efforts by House committees to obtain documents and testimony from administration officials for various investigations into corruption or abuse of power. Resistance has been the posture of the administration ever since Democrats took control of the House in the 2018 midterms and began to launch their investigations.

Trump and administration officials see these investigations as pure harassment, just as Trump complained that the investigation by former special counsel Robert S. Mueller III was a witch hunt, until he, wrongly, claimed that the Mueller report had totally exonerated him. White House resistance has prevented Congress from carrying out its constitutional authority to provide oversight of the executive branch.

Trump has responded to this latest case as he has in previous instances when he has been challenged. He has cast the whistleblower — though he says he does not know the identity of the person who filed the complaint — as a partisan Democrat in an attempt to discredit the allegations of wrongdoing.

Former vice president Joe Biden told reporters on Sept. 21 that President Trump “has violated every basic norm of a president." (Reuters)

He also has refused to say what he said in the call with the Ukrainian leader, other than to assert that whatever it was, it was totally appropriate. “It doesn’t matter what I discussed,” Trump said. And with statements and weekend tweets, he has redoubled efforts to draw attention away from himself and shift it to Biden and Biden’s son. “Someone ought to look into Joe Biden,” he said Friday.

America’s democratic system, the world’s oldest, is said to be resilient, with institutions strong enough to defend against runaway actors and with checks and balances designed to prevent too much power from building up in any one place or with any one person. Earlier in Trump’s presidency, that appeared to be the case. Right now, however, that is in question.

When the president asserts executive privilege to prevent testimony before Congress by a private citizen who never was on the government payroll — as happened this past week when Corey Lewandowski, Trump’s former campaign manager, appeared before the House Judiciary Committee — it is clear how much Trump is prepared to test his belief that his powers are unlimited. “I have the right to do whatever I want as president,” Trump once said, and that appears to be the basis upon which he is operating.

Three years into his presidency, Trump has helped to reveal the weaknesses of the system. In the executive branch, and especially in the White House, there are few if any officials willing to challenge and check the president. To the extent that administration officials could do that, those who tried are gone. He has also demonstrated the degree to which Congress is dependent on a president who operates with some respect for the norms of the system created by the Founding Fathers.

In a Saturday tweet, the president claimed that this latest story is a “witch hunt” by his desperate opponents. At least part of the electorate probably fully agrees with the president on that assertion. Already it’s easy to see the partisan battle lines forming.

In the case of Russia and the 2016 election, Trump campaign associates were certainly open to accepting damaging information about Hillary Clinton, but Mueller said there was not an illegal conspiracy on that question. On the issue of abuse of power, Mueller laid out possible evidence but stopped short of encouraging Congress to move to impeach the president.

The Mueller investigation did not deliver an ironclad case against the president. That is an important cautionary warning in the absence of additional information about this episode. Before all the information is out — if it ever comes out — this is quickly becoming another partisan conflict, more fodder for the coming presidential election.

If it is simply reduced to that, to noise along the campaign trail, then the most important issues will be obscured or ignored, which are how much stress the system already has taken and how much more it can take.