Donald TrumpDonald TrumpToomey: 'No reason' Trump supporters shouldn't back me WATCH LIVE: Trump delivers 'first 100 days' speech in Gettysburg California House Republicans facing tougher headwinds MORE continues to hold a big lead in the race for the 2016 Republican presidential nomination, leading his closest rivals by double digits in an NBC News/Survey Monkey poll released Tuesday.
The billionaire businessman is supported by 35 percent of Republican and GOP-leaning registered voters in the online survey, with Sens. Ted CruzTed CruzIs Georgia turning blue? Five takeaways from money race Club for Growth: Anti-Trump spending proved to be 'good call' MORE (Texas) and Marco RubioMarco RubioRubio: GOP Congress could go in different direction than Trump Poll: Clinton holds 4-point lead in Florida Republicans, it's time to stop asking 'What would Reagan do?' MORE (Fla.) at 18 percent and 13 percent, respectively.
All other candidates poll in single digits, with retired neurosurgeon Ben Carson at 9 percent, former Florida Gov. Jeb Bush at 6 percent, New Jersey Gov. Chris Christie at 4 percent and businesswoman Carly Fiorina at 3 percent.
A third of white evangelicals surveyed, 33 percent, support Trump, while Cruz gets 21 percent and Rubio 10 percent of that group, a key support group candidates are focusing on in the early voting state of Iowa.
Trump is also supported by 35 percent of "very conservative" voters, versus 30 percent for Cruz and 8 percent for Rubio.
The poll comes about a month out from votes being cast in the race in the Iowa causes Feb. 1, where Cruz is the favorite to win, and the New Hampshire primaries Feb. 9, where Cruz and Rubio poll behind Trump.
Cruz and Rubio have largely avoided attacking Trump and have focused their barbs on each other recently, duking it out on the issue of national security and immigration heading into the next debates later this month.
On the Democratic side of the field, Hillary ClintonHillary Rodham ClintonToomey: 'No reason' Trump supporters shouldn't back me WATCH LIVE: Trump delivers 'first 100 days' speech in Gettysburg Dylan's 'Jokerman' a metaphor for Election 2016 and more MORE leads Sen. Bernie SandersBernie SandersHow a new Clinton presidency will change American politics forever Ex-Arizona governor: Hispanic Dems 'don’t get out and vote' Emails show Clinton camp's plans to work with writers to hit Sanders MORE (I-Vt.) 53 percent to 36 percent, with just 2 percent of registered and leaning Democrats supporting former Maryland Gov. Martin O'Malley.
The survey of 3,700 adults nationally was conducted Dec. 28 through Jan. 3 with an overall margin of error of 1.9 points. The margin of error for the 949 GOP registered voters surveyed is 3.7 points and 3.3 points for the Democrats.