A poll on the U.S. Senate race in Arizona released Thursday shows that Dr. Kelli Ward has a nine point lead over her nearest rival for the Republican nomination, which will be determined in the August 28 primary.

Ward leads with 36 percent of the vote, followed by Rep. Martha McSally (R-AZ) with 27 percent, and former Maricopa County Sheriff Joe Arpaio with 22 percent of the vote. Fifteen percent of the voters are undecided.

The poll of 302 likely Republican primary voters was conducted by OH Predictive Insights for ABC 15 Arizona over the two days between April 10 and April 11 and has a margin of error of 5.64 percent.

“Currently, Ward has an advantage of nine points over McSally where Ward’s approval comes from Donald Trump backers. Among those that said they had a very favorable opinion of President Trump, which was 49% of the total sample, Ward took 39% of those voters. Joe Arpaio received 30% of that vote while McSally only acquired 25%,” a statement from OH Predictive Insights/ABC 15 Arizona about the poll noted.

“As candidate’s scrap over who best takes that [Trump] mantle in the [Republican] primary, Kelli Ward is currently able to maximize that over any challenger, and concerns about winning the general may be bringing down Joe Arpaio’s vote. 55% of the likely GOP primary sample had a very or somewhat favorable opinion of Arpaio, but he is only capturing 22% of the GOP primary vote which raises some eyebrows,” the statement continued.

The same poll also looked at the general election contest in November for the Arizona Senate matching the presumptive Democratic nominee, Rep. Kyrsten Sinema (D-AZ) against each of the three leading Republican candidates in a survey of 600 likely voters (including the 302 likely Republican primary voters) that has a margin of error of four percent.

Sinema leads all three GOP candidates, with a six point lead over McSally, 48 percent to 42 percent, a ten point lead over Ward, 50 percent to 40 percent, and a 26 point lead over Arpaio, 59 percent to 33 percent.

According to the statement describing the poll, 74 percent of Independents have an unfavorable view of President Trump, while only 25 percent have a positive of view of him.

As a consequence, the poll shows that 64 percent of Independents support Sinema and 26 percent support McSally in a November general election matchup. Sixty-three percent of Independents support Sinema and 26 percent support Ward in a November general election matchup. Seventy-six percent of Independents support Sinema and 19 percent support Arpaio in a November general election matchup.

The results of the OH Predictive Insights/ABC 15 Arizona Poll for the Republican U.S. Senate primary differ significantly from the results of a Magellan Strategies Poll conducted on April 11, 12, and 15.

The Magellan Strategies Poll shows McSally in the lead with 36 percent of the vote, followed by Arpaio with 26 percent and Ward with 25 percent. The poll of “755 likely Republican primary voters in Arizona” was an “automated voice recorded survey” with a 3.57 percent margin of error.

According to the Magellan Strategies Poll:

The top three issues Republican primary voters want President Trump and Congress to address is enforcing immigration laws (33%), creating jobs and growing the economy (17%) and protecting Second Amendment rights (12%). Among Republican primary voters, 77% think Sen. John McCain should retire and only 19% think he should continue serving in the U.S. Senate.

One explanation for the differences between the OH Predictive/ABC Arizona 15 Poll and the Magellan Strategies Poll could be different geographic sampling within the state.

McSally, for instance, is very well known and popular in Pima County, which accounts for about 15 percent of the GOP primary electorate. Ward, in contrast, is very strong in rural Arizona, which accounts for about 25 percent of the GOP primary electorate.

The breakdown of OH Predictive/ABC Arizona 15 Poll GOP primary respondents was about 15 percent Pima County, 25 percent rural Arizona, and 60 percent the rest of the state. The crosstabs of the Magellan Strategies Poll did not include a geographic breakdown of poll respondents.