"Public Policy Polling surveyed 1,087 voters na tionally, including 524 Republican primary voters and 496 Democratic primary voters, on July 20th and 21st. The margin of error for the overall survey is +/-3.0%, for the Republicans it’s +/-4.3 %, and for the Democrats it’s +/-4.4%. 80% of participants responded via the phone, while 20% of respondents who did not have landlines conducted the survey over the internet. "
20% of respondents via the internet.
And, with those respondents included, margin of error for GOP portion is +/- 4.4%.
Without them, probably over +/-5%.