Washington CNN  — 

A majority of Americans say they think Congress opening an impeachment inquiry into President Donald Trump is necessary, according to a CBS News poll released Sunday.

The poll, conducted by YouGov, shows 55% of Americans think the newly-opened probe necessary, while 45% of Americans think it unnecessary.

On Tuesday, House Speaker Nancy Pelosi announced a formal impeachment inquiry into the President after a transcript of a July call with Ukranian President Volodymyr Zelensky revealed he pushed Zelensky to investigate former Vice President Joe Biden – his potential 2020 political rival – and his son, Hunter. There has been no evidence of wrongdoing by either Joe or Hunter Biden.

A separate whistleblower complaint also alleges Trump abused his official powers “to solicit interference” from Ukraine in the upcoming 2020 election, and that the White House took steps to cover it up. Trump has denied doing anything improper.

Among Democrats, nearly 9 in 10 approve of the inquiry and two-thirds strongly approve – 87% of Democrats approve of the inquiry, according to the poll. Meanwhile, 77% of Republicans disapprove and 23% approve starting an impeachment inquiry. Among Independents, 49% approve and 51% disapprove, the poll found.

Americans split on whether Trump deserves to be impeached over his actions in the handling of matters concerning Ukraine, with 42% saying he does deserve to be impeached over his actions and 36% saying he does not. Twenty-two percent say it’s too soon to say, according to the poll.

When it comes to Trump’s actions concerning Ukraine, 41% – including most Democrats – say he acted illegally while 28% – including most Republicans – say he acted properly, the poll notes. Thirty-one percent say Trump’s actions may have been improper but were nonetheless legal.

A sitting US president does not need to have committed an illegal act to be impeached, but can be impeached for treason, bribery or “other high crimes and misdemeanors.” The House of Representatives votes for impeachment, and if a majority of members vote in favor, the Senate conducts a trial. A two-thirds majority in the Senate is required to convict and remove a president from office – which has never successfully happened.

It remains unlikely that the Republican-controlled Senate would remove Trump from office, even if Democrats in the House impeach him in the chamber.

The CBS poll was conducted between September 26 and 27 and was taken among a nationally representative sample of 2,059 US residents. It has a margin of error of plus or minus 2.3 points.