"Now, what has driven Donald Trump’s decline in his net approval rating? Well, it’s independents. That is the name of the game, baby,” Enten said.

“Look, in January, Donald Trump’s approval rating among independents was about even, minus one point. Not too hot to trot, but not too bad either. Now, we’re talking about 43 points underwater come December. That is a decline of 42 points on his net approval rating,” he added.

Last week, Trump was reported to have the lowest approval rating to end their first year in the last 50 years, according to a Gallup poll. The president reportedly had a 36% overall approval rating among American voters, which tied the percentage he previously set in December 2017 for the lowest among presidents at the end of their first year in office, and a 50% approval rating when he took office in January, which has steadily declined over the course of his second of two non-consecutive terms in office.

Trump was also reported to have his lowest approval ratings ever for his handling of the economy, according to a recent Marist poll. Trump's economic handling is reported to have dropped to 37%, which is the lowest percentage for both of his two non-consecutive terms in office, with 57% disapproving and 10% saying they were unsure.

The president also had a 38% overall approval rating, with 54% of respondents disapproving and 8% saying they were unsure.

“This is a major problem for him,” said Lee Miringoff, director of the Marist Institute for Public Opinion, via PBS News. “When affordability is so front and center in people’s minds, that’s going to be laid at the doorstep of a chief executive.”

Trump's approval rating is also reported to have lost some ground among his 'Make America Great Again' base, according to the latest NBC News Decision Desk Poll powered by SurveyMonkey. Two groups, those who identify as Republican and, particularly, those who claim to be part of the MAGA movement, have seen a significant drop in support since a previous poll conducted in April.

The number of voters who identify more as Republicans than part of the MAGA movement who "strongly approve" of Trump have dropped from 38% in April to 35% in the latest poll, while MAGA Republicans who "strongly approve" of the president have decreased from 78% in April to 70% currently. Additionally, fewer Republicans are identifying with the MAGA movement overall, with the party evenly split at 50% on whether they identify with the movement compared to the traditional Republican Party.