Americans' pride in their country has dropped to historically low levels, according to a new poll by Gallup released just before the country celebrates its 243rd birthday. President Donald Trump and the political divide in America are two big reasons why.

The poll found 45% of U.S. adults say they are "extremely" proud to be an American, sitting below 50% for the second straight year. Seventy percent overall say they are proud.

The numbers were the lowest since Gallup first conducted this poll in 2001.

Different levels of pride can be seen on both sides of the political aisle. Among those who call themselves Republican, 76% say they are "extremely" proud to be an American, and Gallup notes that number never dropped below 68% while Barack Obama was president. On the other side, 41% of Independents and 22% of Democrats said they felt "extremely" proud to be American. That number among Democrats is down 10 points from last year.

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Thirty-two percent of all those polled said America's political system made them proud while 68% say it did not. 

"The decline reflects plummeting pride among Democrats since Trump took office, even as Republican pride has edged higher," Gallup wrote. "While neither party group feels proud of the U.S. political system, politics may be affecting Democrats' overall sense of pride in their country more than Republicans', given Democrats' low approval of the president."

Gallup also notes that Trump's low approval rating internationally may also be playing a role. Gallup says a poll earlier this year showed 31% of Americans -- and just 2% of Democrats -- think foreign leaders respect Trump.

"Absent a significant national event that might rally all Americans around the flag, given Democrats' entrenched views of the president, these historically low readings on American pride are likely to continue until Trump is no longer in office," Gallup noted.

But there are things a majority of Americans did say they had pride in -- America's scientific achievements; its military; arts and culture; economic achievements; sports achievements; and diversity in race, ethnicity and religion.