These numbers are from the newest national YouGov Poll. It was done between July 31st and August 4th of about 400 registered Republican voters (and about an equal number of registered Democrats). No margin of error was given for just Republicans (or just Democrats) -- although the results mirrors what has been reported by numerous other polls.
There is one word of caution I give you about this Republican poll -- it was done before the Republicans debated on Thursday night. Will that debate change how Republicans view their candidates? We'll just have to wait to see, but I think it could.
The survey's results for Democratic voters is shown below.