I noticed this in the November 8th Washington Post Daily 202:
Trump's demands for Ukraine came down to three words -- "Investigations, Biden and Clinton" – according to Deputy Assistant Secretary of State George Kent, who oversaw Ukraine policy. The transcript of his deposition, published yesterday afternoon, lays out in perhaps the starkest terms to date Trump's shadow efforts to coerce Ukraine's leadership to open investigations that would benefit him politically, Greg Jaffe and Mike DeBonis report: "Trump 'wanted nothing less than President Zelensky to go to a microphone and say investigations, Biden and Clinton,' Kent told House impeachment investigators.
One word in that summary jumped out at me - Clinton.
The whole impeachment is based on the conviction that President Trump was trying to use foreign policy to damage a political rival. The President's defenders say that he was simply interested in ending corruption in Ukraine, particularly if it also involved former US officials. The fact that one of them is running for president is irrelevant to an inquiry into past misconduct.
There are some things in favor of the pro-Trump version of the events. Joe Biden did brag about getting a prosecutor fired, there had been an investigation into Burisma, the company that had hired Joe's son Hunter and the State Department had issued a warning about possible conflicts of interest with Hunter being employed by a major company in a country when Joe was responsible for Ukraine policy.
The pro-impeachment people insist that the Bidens did nothing wrong and that Trump was asking a foreign power to help with the US election.
Here's why Clinton's name is so important. Hillary was not running for President in July when the phone call was made nor has she done more than say that she'd love to be President if it were handed to her but she's not running.
If the call was all about hurting a rival then why bring Clinton into it? Her only involvement would have been during her days as Secretary of State or possibly through the Clinton Foundation. That is all in the past. Lumping the two together means that Trump was interested in past misdeeds, not hurting a possible rival.
One last point, Biden is not a political rival. He is a potential rival. He is a front-runner but not a single vote has been counted. Hurting Biden at this point does not help Trump unless you believe that Biden is the only candidate who can beat Trump. Personally I think that Biden would not stand a chance against Trump but hurting him early in the primaries could help someone with a better chance against Trump in the general election. That means that hurting Biden now would potentially hurt Trump later.
I don't believe for a moment that Trump hasn't considered this. So if he wants Ukraine to investigate Biden and Clinton then it's because he genuinely believes that they were involved in some corrupt dealings and wants them punished for it.