Hillary Clinton's trustworthiness issues have dramatically reduced the Democratic front-runner's lead over the summer months.

While Clinton held a 60-point lead over Bernie Sanders in June, she now leads him by a mere 15 points nationally, according to a poll released on Sunday. If Joe Biden were to enter the race, Clinton's lead would shrink to 7 points.

This sharp decrease in support since the beginning of the summer directly correlates to the revelation of details surrounding the former of secretary of state's private email server. Sanders, on the other hand, has seen a dramatic surge of support amongst Democratic voters due to his far-left policies that appeal to progressives and his large rallies, which attract thousands of voters. As a result, Sanders currently leads Clinton in New Hampshire and is gaining significant ground on her in Iowa.

In the GOP, Donald Trump and Ben Carson are neck in neck the lead of the race, followed by Carly Fiorina and Marco Rubio, who are both tied for third place. Trump falls at 21 percent, Carson has 20 percent, and Fiorina and Rubio both have 11 percent of the Republican primary vote. The poll shows a significant change since Scott Walker's exit from the race, as the Wisconsin governor held 15 percent of the GOP vote and held second place in the same July poll.

Behind the Republican front-runners, Jeb Bush holds 7 percent of the vote, John Kasich has 6 percent and Ted Cruz has 5 percent. None of the other eight Republican primary candidates earned more than 3 percent of the primary vote.

The NBC/WSJ poll was conducted September 20th-24th among 256 Democratic voters and 230 GOP primary voters. This is from an early release of the poll and the full results will be released on Monday evening.