Trump was impeached for the second time this past Wednesday for his role in "inciting" the 6 January storming of the US Capitol, although just 50 percent of respondents said that they would support the removal of the president from office, the broadcaster said.
Fewer than one in 10 Republicans believe that the president should be convicted by the Senate, compared to nearly nine in 10 Democrats, the broadcaster said.
The poll was conducted from 10-13 January, in the immediate aftermath of the violent unrest in Washington that reportedly left five people dead.
The House of Representatives first impeached Trump in late 2019 for pressuring Ukrainian President Volodymyr Zelensky to investigate the links Joe Biden and his son Hunter Biden had with the Burisma energy company.
At that time, a poll found that 48 percent of respondents were in favour of removing Trump from office.
The Senate must vote to convict Trump, although Mitch McConnell, the Republican Senate leader, has said that there is little chance of a fair trial being conducted before Biden, the president-elect, is sworn in on 20 January.