Arizonans’ opinions of U.S. Sens. John McCain and Jon Kyl are plunging, according to a Rocky Mountain Poll released Thursday.

Graphic: See the approval ratings of Sens. McCain and Kyl

Read Paul Giblin's Checking In Blog

McCain’s favorable rating among voters fell from 49 percent in March to 42 percent in July. At the same time, his negative rating increased from 18 percent to 30 percent.

As recently as January 2005, McCain’s favorable rating was an eye-popping 73 percent and his negative rating was 6 percent.

Meanwhile, Kyl’s favorable rating fell from 46 percent in March to 40 percent in July. His negative ratings increased from 12 percent to 18 percent.

Republican political consultant Jake Logan said the Republican senators’ images have suffered because of their high-profile roles in the Senate’s failed immigration reform legislation.

“I think they did the right thing. And I think a lot of Arizonans do, but anytime you take a leadership position on an issue like that, some people are bound to disagree with you,” said Logan, who served as Kyl’s campaign manager during his 2006 reelection against Democratic challenger Jim Pederson.

Kyl served as one of the chief authors of the immigration reform legislation, which would have bolstered border security, offered a path to citizenship for millions of illegal immigrants already living in the United States, and created a guest worker program for foreign nationals to work legally in the country.

Both McCain and Kyl took vocal roles in support of the legislation.

Both senators’ ratings are likely to rebound as other issues attract public attention, said Logan, a partner with the Phoenix-based political consulting firm Molera Alvarez Group.

Jim Haynes, president of Behavior Research Center, which conducted the poll, attributed McCain’s plunge to an array of factors, topped by immigration reform and the Iraq war.

Haynes said the poll also clearly indicates that while McCain has a strong position among Arizona Republicans, he is losing his luster as a centralist.

Approximately 51 percent of Republicans rated McCain’s overall performance as “excellent” or “good,” and 20 percent of Republicans rated him as “poor” or “very poor.”

However, among Democrats, 34 percent rated him favorably, but a 42 percent rated him negatively. Among independents, 23 percent were up, but 41 percent were down.

McCain’s fortunes in Arizona reflects his fortunes across the country, said Marcia Weeg, executive director of the Arizona Democratic Party.

“People are asking the question: Who is John McCain? It really used to be, I think, that people had a strong sense of who McCain was. He was really seen as independent, a maverick, a free thinker,” Weeg said.

“Since he’s been running for president, he has been much less likely to speak his own mind than he is to speak about whatever it is the consultants seem to be putting in his mouth at the time,” she said.

Overall, Kyl’s negative marks were lower than McCain’s negative marks.

Among Republicans, 55 percent rated Kyl “excellent” or “good,” while 9 percent rated him “poor” or “very poor.” Among Democrats, 22 percent were up, while 31 percent were down; and among independents, 31 percent were up, 16 percent were down.

Overall, Kyl’s popularity has bounced between 49 percent and 40 since topping out at 49 percent in January 2005.

The latest Rocky Mountain Poll was conducted from July 27 to Aug. 4. The poll of 629 voters has a margin of error of 3.9 percentage points, according to the polling firm.