Republican presidential frontrunner Donald Trump leads Hillary Clinton head-to-head, garnering 45 percent support versus 40 percent of his Democratic rival, according to a new national poll.

The new poll, conducted by Survey USA, marks a significant turnaround in the polls.

Thirty percent of respondents believe Trump will finally be selected as the Republican nominee, according to the poll released on Friday.

While the popularity of Trump campaign increased through the summer, Clinton could not improve her image among likely voters over her lack of transparency and trustworthiness as former secretary of state.

According to a CNN/ORC sampling of national voters conducted in late June, just days after Trump entered the competition, 59 percent backed Clinton as opposed to 34 percent who supported Trump in a head-to-head matchup.

In July, the same polling organization put Clinton at 57 percent to Trump at 38 percent with another one in August showing Clinton with 52 percent support and Trump with 43 percent.

The Survey USA poll shows that Trump has also beaten Senator Bernie Sanders (I-Vt.) by 44 percent to 40 percent; Vice President Joe Biden by 44 percent to 42 percent; and former Vice President Al Gore by 44 percent to 41 percent.

This comes as another survey revealed Thursday showed Trump has hit a new high in the race to the Republican presidential nomination.

According to the survey by Monmouth University, the businessman now enjoys a 30 percent support nationally.

The poll showed that Trump is also the lead candidate in ideological categories, revealing that Tea Party supporters, and Republicans prefer the billionaire as their future president.

Clinton has come under fire from her Republican rivals since it emerged in March that the former secretary of state used a personal email account on an unsecured private server for official business.