A conspiracy theory years in the making is being pushed by President Donald Trump and his allies.
That discredited theory blames Ukraine, and not Russia, for plotting to keep Trump out of the White House in 2016.
High-ranking U.S. security officials, including Trump's FBI director, say there's nothing to support those claims.
In fact, U.S. intelligence services agree Russia is the one that interfered in the 2016 elections.
Still, the unsupported claims have muddied an impeachment case against Trump sparked by his request that Ukraine investigate Democrat Joe Biden, who could become Trump's 2020 election opponent and whose son sat on the board of a Ukrainian company.
