Other than Clinton, none were ever indicted for any wrong doing. Arguing that, like Trump, they were attacked muddies the water on Trump's felonies.
One answer might be that Clinton, like Trump had one set of trials dealing with allegations of inappropriate sexual behavior in the Paula Jones case. One difference is that the courts ruled that the Jones case could go on even when he was President. Had that case NOT happened then, there very likely would have been no impeachment.
Like Trump, Clinton was also attacked with the white water allegations. Unlike Trump and his various fraudulent business activities, neither Clinton was ever indicted. Trump University was closed as a fraud even while Trump was President. Trump and many family members can not sit on the board of a NY charity because the Trump Foundation was quilty.
These felonies that he will now be sentenced for were crimes that Trump's own justice department went after Michael Cohen for because Cohen helped him hide payments to Stormy Daniels. If it was a crime for Cohen, how can it be just political that Trump was charged?
There is also the mammoth tax and business fraud case in NYS. That is a civil case, but the Trump business was found guilty and was to pay a huge fine. I haven't heard the status of that case, but I assume it is still out there. The business trial came down to proving fraud using the accounting records from the company. This was not political.
What was political in the same time frame was the Comer hearings that tried to twist anything they could to prove Joe Biden used his positions for political gain. They were desperately seeking something where they could impeach him. They found nothing.