Donald Trump continues to show strength among Republican primary voters, holding a slim lead over Jeb Bush and a comfortable 6 point lead over Scott Walker.

The new CNN poll out today shows Trump with 18% and Bush at 15%. Walker trails with 10%.

None of the other 14 candidates tested in the new CNN/ORC survey earned double-digit support.

Though Trump currently tops the race for the nomination, his advantage is by no means firm. A majority of Republican voters, 51%, say they see the field as wide open, and that it's too soon to say which candidate they will ultimately get behind. Among that group that see the contest as wide open, Bush has 14% support, while Trump has the backing of 13% and Walker stands at 9%.

Trump does much better among those Republicans who say they've narrowed it down to one or two candidates, 24% of that group backs him, 16% Bush and 12% Walker.

READ: Full poll data

Trump's popularity among Republican voters does not translate to the broader pool of registered voters. When tested in hypothetical general election matchups against top Democrats, he trails both frontrunner Hillary Clinton and upstart Senator Bernie Sanders by wide margins. Bush and Walker run just behind Clinton and about even with Sanders.

Trump's unfavorability rating is sky high. Overall, 59% of all registered voters have an unfavorable opinion of Trump, though that dips to 42% among GOP voters.

None of the other Republicans landing near the top of the field have such a negative image nationwide, though many remain little known.

Clinton is the only candidate who is about as well-known as Trump, and while she is more well-liked than the developer, her favorability rating is net negative among registered voters nationally: 49% have an unfavorable view while 44% have a positive impression.

Part of the advantage Trump is exploiting is that he has no record that opponents can pick through to criticize. Like Obama in 2008, he's a blank slate that voters can project on him anything they want. And many GOP voters, angry at everyone - including many members of their own party - see Trump as the embodiment of that anger.It hardly matters where he stands on specific issues. All they know is that his anger seems genuine and he speaks the language of internet political combat - name calling, dispargement, and ridicule.

How far can this take Donald Trump? Money won't be a problem. And according to this Marist poll, he is running ahead in both Iowa and New Hampshire, so a couple of early victories might build momentum for a long run.

Political experts predict a Trump meltdown, but from these polls results, you would think he'd be nearly immune. In fact, a meltdown that would permanently damage another candidate might only reinforce support for Trump among his voters.

It's going to be a very intreresting summer.