US Senate Minority Leader Chuck Schumer delivers a press conference after the Senate impeachment vote on Capitol Hill in Washington DC on Wednesday. Photo: AFP

 
President Donald Trump was acquitted by the US Senate on Wednesday following a historic impeachment trial that shone a harsh light on America's divisions, without ever shaking the loyalty of his voter base.

In a political triumph for the US leader, Trump drew on staunch Republican support to easily defeat a Democratic ­effort to expel him from office for pressuring Ukraine to help bolster his re-election effort.

The president immediately claimed "victory" while the White House declared it a full "exoneration" - and Democrats rejected the acquittal as the "valueless" outcome of an unfair trial.

But the vote in the Senate showed just how solid a grip the former real estate mogul holds over the Republican Party - an asset nine months before he seeks a second four-year term.

Even though several conceded Trump's behavior was wrong, Republicans ultimately stayed loyal in voting to clear the president of charges of abuse of power, by 52 to 48, and of obstruction of Congress, by 53 to 47 - far from the two-thirds supermajority required for conviction.

"Two thirds of the senators present not having found him guilty of the charges contained therein, it is therefore ordered and adjudged that the said Donald John Trump be, and he is hereby, acquitted," said ­Supreme Court Chief Justice John Roberts.

One Republican, Senator Mitt Romney, a longtime Trump foe, risked White House wrath to vote alongside Democrats on the first count, saying Trump was "guilty of an appalling abuse of public trust." He voted not guilty on the second charge.

Trump's impeachment and trial will leave a permanent stain on his record, as it did for the only two presidents to have encountered the same fate, ­Andrew Johnson in 1868 and Bill Clinton in 1998.

But the Senate verdict was never truly in question since the House of Representatives formally impeached Trump in December, and it has now cleared out a major hurdle for the president to fully plunge into his campaign for re-­election in November.

While the White House declared that Trump had obtained "full vindication and exoneration," Nancy Pelosi, the House Speaker, warned that by clearing Trump Republicans had "normalized lawlessness."

"There can be no acquittal without a trial, and there is no trial without witnesses, documents and evidence," said the top Democrat in Congress - who a day earlier ripped up her copy of Trump's State of the Union address on live TV. 

"Sadly, 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." 

Senate minority leader Chuck Schumer said the acquittal was "virtually valueless" since Republicans refused witnesses at his trial, something which Democrats said had never happened before at any impeachment trial.