There is still time to hope that President Donald Trump’s legal team will mount a serious, evidence-based defense when its turn comes in the Senate impeachment trial.

Even supporters of the president must be discomfited by the White House refusal to provide any evidence or documents, and by Trump’s determination to block every key witness and to intimidate those who do come forward. That is simply not how people who believe in their innocence act.

The absence of a serious defense would taint the acquittal that Senate Majority Leader Mitch McConnell, working hand-in-glove with the defendant, appears determined to force at any price.

But the damage would go beyond that. It would show that the presidency is no longer accountable to other branches of government. It would set a terrible precedent for a president stonewalling his — or her — way through any accusations by simply labeling them a witch hunt and depriving accusers of any potentially incriminating materials or testimony.

It’s not just Trump who’s on trial here. It’s American values being tested, and the rest of the world is watching. Republicans have made it clear that even though some of them have acknowledged they believe the president’s actions were wrong, they do not rise to the level of removal from office. They will have to defend that decision to the public, but it is their choice to make.

However, that choice should be made only after a careful consideration of the case. Read the documents. Hear the testimony. Analyze the evidence. An impeached president is on trial for only the third time in the history of this republic. That is a grave matter. Any American who has served on a jury knows what would happen if they dared to toy with a fidget spinner during a trial (Sen. Tom Cotton), or break out a book (Sen. Marsha Blackburn) or simply get up and walk out. They could be facing contempt of court, mostly likely while a bailiff was dragging them off to jail.

House managers, under the most difficult of circumstances, have been diligent in presenting their case, including video clips of the few witnesses who were brave enough to appear before Congress. They have done a credible job. Meanwhile, Senate Republicans have voted down efforts to obtain documents from the White House, the State Department, the Office of Management and Budget and the Defense Department. They have rejected attempts to obtain testimony from key witnesses, including acting White House Chief of Staff Mick Mulvaney and former national security adviser John Bolton, who has said he will testify if subpoenaed.

Americans deserve more from their leaders. They may be divided on whether Trump should be removed. But they have been clear about witnesses: Two-thirds believe new witnesses should be called to testify in the Senate trial. Trump’s refusal to cooperate is unacceptable, and in a sense eclipses in magnitude whatever actions he undertook regarding Ukraine.

It is a rejection of the principle that the president — like anyone else in this country — is accountable for his actions and subject to the rule of law. The rest is noise and obfuscation.