Hillary Clinton has taken an average seven point lead over Donald Trump in the critical battleground states of Iowa, Ohio and Pennsylvania.

According to a trio of new NBC/Wall Street Journal/Marist polls taken since both party conventions were held late last month, Clinton now leads Trump 41 percent to 37 percent in Iowa, 43 percent to 38 percent in Ohio and 48 percent to 37 percent in Pennsylvania.

Clinton Surging 

In the same polls taken before either convention, Clinton led Trump by an average of just four points, with the two actually locked in a tie in the state of Ohio.

"These three states are key ingredients in Trump's formula for success and a region where Trump was hoping [running mate Mike] Pence would provide a boost," said Lee Miringoff, director of the Marist College Institute for Public Opinion. "Yet Trump is coming up short in his bid to change the electoral map. Given that Clinton has many more paths to the White House, these poll results are a warning sign for the Trump effort."

While both candidates find themselves greatly underwater with voters in terms of their net favorability, Trump's prove to be much more pronounced.

In Iowa he has an overall unfavorable view of -33 compared to Clinton's -22, while in Ohio and Penn., Trump's average rating is -32 compared to Clinton at -22.

The NBC/WSJ/Marist polls were conducted from Aug. 3-7 and consisted of 899 registered voters in Iowa and Ohio and 834 in Pennsylvania. Each of the polls has an average margin of error of 3.5 percent.

Clinton up 10 Points in CNN Poll 

Meanwhile, a recent CNN Poll of Polls survey found Clinton has increased her lead over Trump to 10 percent and is now on the verge of cracking 50 percent of the overall vote.

Pollsters found Clinton now leads Trump 49 percent to 39 percent in an average of six recent polls conducted after both party conventions ended late last month. A similar poll conducted before either convention was held found Clinton besting Trump just 45 percent to 41 percent.

In recent history, the candidate found to be leading in the polls after both conventions have concluded has gone on to ascend to the White House.