Donald Trump is taking a nosedive in the polls

After a week that began with a major staff shakeup and a dismal report on his finances, Donald Trump is taking a hit on one of his favorite stump-speech topics: His poll numbers.

A new Washington Post/ABC poll published on Sunday found Trump trailing former secretary of state Hillary Clinton by double digits in head-to-head matchups among national adults.

Support for Trump fell from 44% in May to 39% in June, while Clinton's support jumped from 46% to 51% - a 10-point month-to-month swing. Almost two-thirds of voters said he is not qualified to serve as president, while 70% of respondents said the thought of him as president makes them "anxious."

The Post/ABC poll published Sunday is the latest in a series of surveys showing the presumptive Democratic presidential nominee pulling ahead of her Republican counterpart in national surveys.

An NBC/Wall Street Journal poll also published on Sunday found the real-estate magnate trailed Clinton by 5 points, down from 3 points in May, while a Reuters survey on Saturday found Clinton ahead by 13 points among likely voters.

Following the mass shooting at an Orlando nightclub earlier this month, Trump appeared to experience a brief, slight bump in popularity. But more recent surveys found that Trump's toxic image among female and minority voters was hindering him from gaining an edge over Clinton.

A Monmouth University poll released last week found that 49% of registered voters thought that it is "very important" to make sure Trump is not elected president, while 41% of respondents felt similarly about Clinton.

For his part, Trump maintained that reporters were over analyzing his poor national poll numbers.

In a "Today" show interview last Tuesday, the real-estate magnate noted that he is still tied with Clinton in battleground states like Ohio and Pennsylvania, despite tough news cycles that focused on his inflammatory comments about a federal judge and his response to the Orlando shooting.

"I'm right there, with the horrible few weeks I've had with the press," Trump said. "Pennsylvania, Ohio - we're practically even," Trump said.

But while analysts tend to agree that surveys of key battleground states are more important to watch as Election Day nears, some point out that national polls can give a good sense of the electorate's mood before pollsters begin increasing the number of state polls.

"Generally, it would be ideal to watch battlegrounds such as Ohio/Florida/Pennsylvania. However, state polls are sparse," Princeton University polling expert Samuel Wang told Business Insider in an email earlier this month. "This year's states are mostly correlated with 2012, so there's no realignment. This means that watching national numbers is probably a reasonable substitute."