US House Speaker, Nancy Pelosi has frowned at the acquittal of President Donald Trump by the Senate.
Democrats had alleged he withheld military aid to Ukraine and asked the country to move against Joe Biden, his political rival.
They impeached President Trump in the House after he was impeached in the House of Representatives.
But on Wednesday, Senators voted that he was not guilty of abuse of power and obstruction of Congress.
Mitt Romney was the only Republican to vote against Trump in the 52-48 vote.
The Senate needed a two-third vote to remove Trump from office.
In her reaction, Pelosi called him a “rogue president” and said he was a “threat” to America.
She said: “Our Founders put safeguards in the Constitution to protect against a rogue president. They never imagined that they would at the same time have a rogue leader in the Senate who would cowardly abandon his duty to uphold the Constitution.
“President Trump was impeached with the support of a majority of the American people – a first in our nation’s history. And now he is the first President in history to face a bipartisan vote to convict him in the Senate.
“The President will boast that he has been acquitted. There can be no acquittal without a trial, and no trial without witnesses, documents and evidence.
“Because of the Republican Senate’s betrayal of the Constitution, the President remains an ongoing threat to American democracy, with his insistence that he is above the law and that he can corrupt the elections if he wants to.
“The House will continue to protect our Constitution & #DefendOurDemocracy, both in the courts of law and in the court of public opinion.”