The case for removing Donald Trump from office, whatever one's feelings about is fitness for office, is not cut and dried.
What seems generally accepted is that Trump used the power of his office to pressure a foreign government to provide dirt on a political opponent and then sought to prevent Congress from looking into what he had done.
One interpretation, that advanced by the House Managers, raises three issues; that Trump abused the power of the office by using it for personal gain, that he was inviting foreign meddling in a US election, and by stonewalling Congressional requests for information and testimony, he was obstructing Congress which has the right (and the duty) to hold the executive branch to account.
However, there are reasons to suggest that impeachment and a verdict of removal from office would be inappropriate.
First, with respect to Article 1, there is the central question of motive. If asking for an investigation into Joe and Hunter Biden was in part motivated by a desire to deal with corruption, then the act, even though it had as a 'side-effect' of benefitting Trump in the upcoming election, might not qualify as an abuse of power. If it cannot be definitively ruled out that an element of Trump's intent to further the rooting out of corruption, something that would be (and has been) a legitimate US foreign policy goal, his conditioning official acts on Zolensky opening of an investigation could be seen as a legitimate exercise of the power of the office. Thus the first article, abuse of office, cannot be definitively proven. While the most probable interpretation of Trump's actions is that it was solely about political gain and not corruption in general, it is unclear that this can be determined beyond a reasonable doubt, with or without the testimony of Bolton, Mulveny, and Pompeo and others who might provide corroboration. Proving intent here is difficult.
Second, with respect to Article 2, it has been argued that in the absence of a case for the first article, the second is moot; if there was no offense, there could be no cover-up, even if the scope of the refusal to cooperate with Congress want far beyond historical precedent and the normal exercise of executive privilege. The problem with this argument is that the determination of whether there was an offense or not cannot be left to the defendant, the Executive branch in this case, but must be made by the prosecution, the House.
Perhaps a better defense is that Congress' right to demand information from the Executive branch has not been fully tested in court. While the Supreme Court ruling on the Nixon tapes suggests that the Executive's prerogative to withhold information from Congress is not without exception, the limits of what must be divulged and what may be withheld may still be subject to debate and adjudication. And since the House did not pursue its request through the judicial branch, the case for obstruction can't be made since it is not clear that the House has an indisputable right to the information it sought.
While utterly farcical, Alan Dershowitz' argument that if the president believes his reelection is in the "public interest" then any action he takes in pursuit of that end is is, by definition, in the public interest and therefore not impeachable could be applied to both articles. The original abuse of power was intended to help Trump get reelected, and the exposure of this act would have damaged his reelection chances, so covering it up was also material to his reelection. Thus both articles are nullified according to the Dershowitz doctrine. The Dershowitz theory, fortunately, is unlikely to survive the test of time, public opinion or the courts.
So while to many the preponderance of circumstantial evidence points to Trump's guilt on both counts, it is perhaps not incontrovertible; and if not proven beyond a reasonable doubt, then perhaps removal from office is not an appropriate remedy.
The case for impeachment is not cut and dried, but US democracy is left torn and tacky.
