In Hollywood, it is called a false ending — where the story appears to be heading to a close but is not yet over.

President Donald Trump's impeachment trial ended on Wednesday with a conclusion that was unsurprising: his acquittal. But in reality the end of the story will play out in November, when American voters go to the polls.

That is when Democrats will finally learn whether their gamble to impeach a president for the third time in U.S. history paid any electoral dividends in winning over undecided voters. Opinion polls during the impeachment proceedings suggested little political harm to Trump — opinions among Republicans and Democrats were largely entrenched from the outset.