President Donald Trump at a press conference in the White House. Mark Wilson/Getty Images

President Donald Trump's approval rating — at 40%, according to Gallup — is 21 percentage points below the historical average for presidents one month into their tenure, as he ends a rocky opening month marked by a high-profile legal battle and the resignation of his national security adviser amid questions over his ties to Russia.

Presidents Bill Clinton and Ronald Reagan held the previous lows, at 51% and 55%, respectively, since Gallup began surveying in the 1950s.

"It is clear that Trump has not enjoyed the same honeymoon phase his predecessors had — and to the extent he has had one, it has only been among his fellow Republicans. Trump's approval ratings are substantially lower than any prior president's at this point in their administration," Gallup's Jeffrey M. Jones wrote.

In line with Gallup's poll, a recent Pew Research survey showed that current views of Trump are deeply polarized and much more negative than positive.

That poll of 1,503 adults found that while Trump's approval among Republicans and Republican-leaning voters was in line with past presidents' approval ratings within their own parties, his approval rating among Democrats and Democratic-leaning independent voters were at record lows. Seventy-five percent of those surveyed felt strongly either about their approval of disapproval of Trump.

Trump's now-scrapped executive order on immigration, which banned most travel from seven majority-Muslim nations, was more unpopular — 38% approved and 59% disapproved — in the recent Pew poll than in polling two weeks ago.

The Pew poll also found that large majorities, ranging from 56% to 68%, find fault in Trump's character — saying that he is not even-tempered, not a good communicator, not trustworthy, not well-informed, and does not care about "people like me."

The poll also found that a majority are concerned about Trump's conflicts of interest and respect for democratic institutions.

But on the economy, Trump's approval ratings were higher — 43% approve of how he is handling the economy, while 47% disapprove.

The sharp demographic split among those surveyed reflects patterns in surveys throughout the election, with the majority of racial minorities, people under 49, and women holding unfavorable opinions of Trump and the majority of white people, men, and whites without a college degree holding favorable opinions.

At a press conference on Thursday, Trump cited a 55% approval rating from Rasmussen's daily presidential tracking poll. But the Rasmussen poll stands as an anomaly. The Real Clear Politics average of 11 major polls puts Trump's approval rating at 44.6% and disapproval rating at 50.3%. Coming into office, Trump had the lowest and only net-negative rating for a new president in recent history.

Trump denounced low approval ratings as "fake news" in a series of tweets last week, after dismissing polls in January that showed he would be the lowest-rated incoming president in modern history.