The Trump defense against impeachment is premised on layers upon layers of nonsense, but the notion that Donald Trump's act—suspension of military aid to a foreign nation until its government announced an investigation of his just-announced domestic political opponent—does not constitute a crime is among the most blatant.
Bribery. The crime is that Donald Trump demanded a personal bribe in exchange for an official act of his office. And soliciting a bribe is, unequivocally, a criminal act.
The defense theory that Trump was allowed to target a specific political opponent for an "investigation" as a supposed foreign policy is inherently corrupt. There is no other word for it. Criminal defender Alan Dershowitz went further still, claiming that if Trump believed that his winning reelection was genuinely in the public's best interest, then any action he took to sabotage his opponents would be legal and allowable. In every other public context, this is recognized unequivocally as an act of corruption.
Ex-House Republican Chris Collins was indicted for insider trading—using private information to make stock trades meant to benefit himself. Ex-Rep. Duncan Hunter was indicted for stealing, outright, campaign funds for his own personal gain. The then-governor of Illinois, Democrat Rod Blagojevich, was impeached, removed, and imprisoned for seeking to trade political appointments, an official act of his office, for personal bribes.
It is Blagojevich's case that is a close analogue to what Trump himself did. Trump unilaterally delayed military aid allocated by the House and Senate to a foreign ally. Trump distanced his White House from that government, refusing a meeting the newly elected Ukrainian leader considered of utmost importance in signaling to Russia that his nation had the support of the United States. He withheld both acts, indisputably now, to procure an announcement from the Ukrainian government that his potential election opponent was now being investigated for corruption.
That is soliciting a bribe. Trump could have requested that his Department of Justice "investigate" his election opponent itself; it would still likely be a crime. Trump could have made the request without using the tools of his office to pressure the desperate Ukrainian government into compliance; doing so in his official capacity as president would still likely be a crime. Trump did the most corrupt of all versions, however.
Trump demanded that Ukraine announce two specific investigations, one of Biden and one promoting an anti-Democratic Party conspiracy theory boosted by the same Russian government known to have targeted Trump’s election opponents in the past. The only investigations Trump demanded were focused on his domestic political opponents.
Trump coordinated the effort not through the United States' robust law enforcement and foreign policy agencies, but through his personal lawyer, working with now-indicted Ukrainian criminals, coordinating "evidence"-gathering with a known-to-be-corrupt Ukrainian official seeking to trade that evidence to Trump's team in exchange for getting his own criminal indictment squashed by Trump's Department of Justice. This gaggle of criminals was elevated above the official United States foreign policy apparatus, and quickly succeeded in getting a member of that foreign policy apparatus, the U.S. ambassador to Ukraine, removed from her position by convincing Trump she was a political, not a policy, opponent.
Trump ordered multiple members of his Cabinet to take official actions, actions determined at the time to be baseless and soon afterwards judged to be illegal, intended to put maximum pressure on Ukraine to comply in providing the “favor’ he’d asked for. He ordered his subordinates to perform official acts meant to extort Ukraine into compliance—literally at gunpoint.
Trump provided no public explanation for his acts, Trump's subordinates provided their own government subordinates no private explanations for those acts; an after-the-fact effort was launched to investigate any possible rationale that could be offered for his acts; White House officials swiftly moved to conceal his acts as numerous White House and government officials alerted White House lawyers of the potentially criminal nature of those acts; and when Congress eventually learned of his acts, Trump offered no explanation, but instead ordered all agencies to refuse document requests, subpoenas for testimony, and other basic tools of oversight.
Donald Trump sought a bribe from Ukraine. Donald Trump demanded that the government of Ukraine grant him two very specific personal favors, both targeting his election enemies, and withheld official acts of his government to procure them. Trump ordered his administration to take official acts to obstruct congressional investigation of those acts.
Seeking something of personal value in exchange for performing an act as a public official is seeking a bribe. It is not hard to understand. It does not matter if it is called a new "foreign policy" in which personal bribes are, now, supposedly both official policy and good for the country.
It's bribery. Just say it. And every Republican senator either knows full well that Trump was soliciting a bribe or, by denying it, has indicated that they too are sufficiently corrupt to consider demanding precisely the same thing in exchange for doing their own official duties.
That is likely the case. It is evident, at this point, that nearly every Republican senator both stipulates that Trump did exactly what John Bolton claims to be an eyewitness to and is taking the official position that members of their party are indeed allowed to solicit such "favors" without repercussion or recourse. But it is unambiguously bribery, and each of them is now conspiring in that act.