Donald Trump has jumped further ahead in recent polling, gaining a 2-1 advantage over closest Republican challenger Marco Rubio in their ongoing battle to secure the GOP's 2016 presidential nomination.

A new Quinnipiac poll shows Trump at 39 percent to Rubio's 19 percent and 18 percent for Texas Sen. Ted Cruz. The new figures represent the highest level of support Trump has registered in the polls since jumping into the race in late summer.

Ohio Gov. John Kasich currently stands at 6 percent, followed by former Florida Gov. Jeb Bush and retired neurosurgeon Ben Carson at 4 percent each.

"Reports of Donald Trump's imminent demise as a candidate are clearly and greatly exaggerated," said Tim Malloy, assistant director of the Quinnipiac poll. "Like a freight train barreling through signals with his horn on full blast, Trump heads down the track towards a possible nomination."

The outspoken real estate mogul earns a 62-31 favorability rating among GOP voters, compared to a 64-17 rating for Rubio and a 62-23 score for Cruz.

GOP Voters Confident Trump Will Win

In addition, 77 percent of Republican voters think Trump stands a good chance of winning November's general election, while 61 percent say Rubio has a better chance. Cruz is not far behind with 60 percent.

Eight in 10 Republican voters also agree Trump has strong leadership qualities, compared with 69 percent for Cruz and 60 percent for Rubio.

Close Race Among Democrats

On the Democratic side, Hillary Clinton now leads Bernie Sanders by just two points nationally, at 44-42 percent, with 11 percent of voters insisting they still remain undecided.

"Sen. Bernie Sanders and Secretary Hillary Clinton are neck and neck," added Malloy. "But while Bernie has the trust, Hillary has the experience. Two different measurements of two dissimilar candidates."

Meanwhile, data shows Sanders has significantly cut into Clinton's lead among women, the gap now down to six points, 47 to 41 percent, in that critical bloc. He leads by four points, 44 to 40 percent, among men.

Clinton Still Viewed as Presidential

In addition, 93 percent of Democratic voters believe Clinton has the right kind of experience to be president, compared to 74 percent for Sanders.

On the issue of trustworthiness, the liberal Vermont senator leads Clinton 87 to 61 percent, while 87 percent of voters believe the former secretary of state has strong leadership qualities, with 79 percent saying the same of Sanders.

Overall, 83 percent of Democrats believe Clinton stands a good chance of winning the presidency in November, compared to 69 percent who feel the same way about Sanders.

With the South Carolina primaries looming later this month, a recent Public Policy Polling survey found Trump leading the GOP field with 35 percent of the vote and Clinton on top among Democrats at 55 percent.