Having been deeply disappointed by the Mueller report which they believe let Mr Trump off lightly on the Russia investigation, Democrats have struggled to lay a glove on him despite endless Congressional inquiries.
They know that the fast-moving controversy over the Ukraine holds fresh danger for Mr Trump. But Republicans also believe it has the potential to damage Democratic presidential front runner Joe Biden.
The president is under pressure to reveal exactly what he said about Mr Biden to Ukraine president Volodymyr Zelensky in a phone call in late July.
The Wall Street Journal reported that Mr Trump pressured Mr Zelensky eight times in that phone call to investigate the former vice-president’s anti corruption efforts in the country while he was vice president and while his son Hunter Biden was also working there. If true, it amounts to a president using his position to pressure another sovereign country to take action to damage a political rival.
MORE: Impeachment talk after Ukraine phone call
Mr Trump has already confirmed part, but not all, of this story. He has admitted that he raised Mr Biden with Mr Zelensky during the phone call but it is unclear in what context and whether he directly asked the Ukraine leader to look into the Biden affair.
Mr Trump temporarily withheld $US391 million in military aid to Kiev in July for unexplained reasons but has said it was not linked to the Biden issue.
The easiest way to resolve what unfolded is to release the transcript of the phone call. Mr Trump claims he would be happy to release a transcript but others such as Secretary of State Mike Pompeo say it would raise a dangerous precedent which could lead to other disclosures of confidential conversations between the president and world leaders.
Trump has defended his conduct by saying he said nothing wrong in the phone call while also maintaining that Mr Biden’s behaviour in Ukraine is worth of investigation.
Trump and Republicans accuse Mr Biden of pushing for the firing of Ukraine’s then general prosecutor Viktor Shokin to stop a corruption investigation into gas company Burisma, where Hunter was a board member.
They accuse Mr Biden of using his position of power to protect his son. Mr Biden disputes this and neither Mr Biden or Hunter have been accused of wrongdoing by authorities.
Mr Biden says he and others, including America’s European allies, called for Mr Shokin’s ousting because he wasn’t doing enough to combat corruption in the country, not because of any links to the company which Hunter Biden was involved in. Mr Shokin was eventually sacked.
The danger for Mr Biden is not that the facts implicate him in any wrongdoing because as things stand, they don’t. The danger is simply that the president and his allies are pushing the notion that something is smelly and doesn’t add up in the whole affair. They are preparing to turn this into a major issue for Mr Biden as the race for the Democratic nomination heats up in the months ahead. That campaign promises to be damaging to Mr Biden regardless of whether the allegations are true or false.
Meanwhile the Democrats are hugely energised by the reports about the phone call, claiming it is clear that the president acted inappropriately in his dealings with Mr Zelensky.
That story follows revelations than an unnamed intelligence officer filed a whistleblower complaint against the president relating to the contents of that phone call.
The controversy has revived talk among Democrats of launching impeachment proceedings against the president.
But the full facts of the controversy are still unclear. So far Mr Trump has refused to concede that the has done anything wrong and maintains the conversation with Zelensky was “perfect.”
If the president truly believes this, he should have no fear in releasing the transcript to kill this issue before it continues to grow.
Cameron Stewart is also US correspondent for Sky News Australia
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