Trump's approval rating, meanwhile, holds exactly even with where it was in late April 43 per cent approve and 52 per cent disapprove of the President, the poll revealed on Sunday.
Trump's overall approval rating is about on par with Ronald Reagan's rating at this point in 1983, and above Jimmy Carter's 32 per cent at this point in 1979.
Meanwhile, support for impeachment rose slightly from 37 per cent last month to 41 per cent now.
The shift on impeachment stems mostly from a rebound in support for it among Democrats 76 per cent favour it currently, up from 69 per cent in April. Whites who hold college degrees have also increased their support for impeachment.
In surveys in April and March, fewer than three in 10 in that group favoured proceedings, but that number has now climbed to 41 per cent.
Speaker of the House Nancy Pelosi, who has resisted calls to open an impeachment inquiry into the President, sees her approval rating hold mostly steady in the new poll (40 per cent view her favourably, 48 per cent unfavourably).
About two-thirds of all Americans (67 per cent) have said that Special Counsel Robert Mueller ought to publicly testify before Congress, including majorities of Democrats (88 per cent) and independents (62 per cent) and about half of Republicans (49 per cent).
The CNN Poll was conducted on May 28 through 31 among a random national sample of 1,006 adults.
( With inputs from IANS )