Support for Donald Trump’s impeachment has increased over the past month according to the latest opinion polls as Democrats accused Republican senators of violating their oath of office by pledging to work for the president’s acquittal.
The Democrat-controlled House of Representative is expected to vote to send Mr Trump for trial in the Senate this week accusing the president of abuse of power and obstruction of Congress.
Americans remain deeply divided over whether Mr Trump should be removed from office. However, two polls released on Sunday show that impeachment is gathering support, albeit slowly.
A Fox News poll, conducted last week, showed that impeachment and removal from office was backed by 50 per cent of voters - up one point from last month and opposed by 41 per cent, unchanged from November.
Meanwhile, a CBS poll showed 42 per cent of voters in favour of removal and 42 per cent opposed.
However, a separate survey 46 per cent of voters who took part in last month’s poll favoured impeachment, compared with 43 per cent in November.
The polls were taken against a backdrop of battle lines being drawn up for the Senate trial, which is expected to begin early next month.
Senior Republicans have already signalled that their mind is made up, despite a constitutional obligation to act as impartial jurors.
Speaking on Face the Nation on Sunday Lindsey Graham from South Carolina and a close ally of Donald Trump made little pretence of neutrality, saying his mind was already made up.
“ I'm not trying to hide the fact that I have disdain for the accusations in the process. So I don't need any witnesses,” he said.
Last week Mitch McConnell, the leader of the Republican majority in the Senate said he was “coordinating with White House counsel.”
Their stance drew angry condemnation from senior Democrats including Chuck Schumer, the party leader in the Senate.
“If articles of impeachment are sent to the Senate, every single senator will take an oath to render ‘impartial justice’.
“Making sure the Senate conducts a fair and honest trial that allows all the facts to come out is paramount.”
Sherrod Brown, a Democrat from Ohio, said he was disappointed by what he called Republicans’ “see-no-evil, hear-no-evil attitude.”
Having heard a mountain of damning evidence from career government officials, Democrats including Adam Schiff, who chairs the House Intelligence Committee, believes there was no alternative to impeachment.
Mr Trump’s likely acquittal by the Senate would not signal a failure for Democrats, he said on ABC’s This Week on Sunday.
Jerrold Nadler, who chairs the House Judiciary Committee, which drew up the articles of impeachment, defended the decision to send Mr Trump for trial.
“This is not a one-off -- impeachment is not a punishment for past behaviour.”
“He poses a continuing threat to our national security and to the integrity of our elections, to our Democratic system itself,” Mr Nadler added. “We cannot permit that to continue.”
However, a handful of Democrats in Congress are uneasy at the prospect of putting the president on trial including Jefferson Van Drew from New Jersey who is reportedly ready to defect to the Republicans over the issue.
He was one of two Democrats who voted against starting impeachment proceedings.
His imminent defection was hailed by Mr Trump on Twitter. “Thank you for your honesty, Jeff. All of the Democrats know you are right, but unlike you, they don’t have the ‘guts’ to say so!”