After slugging it out with his Republican opponents on his own home turf, Arizona Sen. John McCain is the projected winner of the GOP primary tonight. On the Democratic side, New York Sen. Hillary Clinton has been projected the winner.

Preliminary results of an Associated Press exit poll show John McCain's difficult relationship with conservatives in his home state created an opening Tuesday for Mitt Romney to put up a fight in in the primary.

Romney had strong support from Republicans who described themselves as conservative and those who believe illegal immigrants should be deported.

McCain has drawn the ire of some Arizona conservatives for his views on immigration and campaign finance. He does have overwhelming support from Republicans who described themselves as liberals. McCain also had an edge over Romney among moderates.

Romney was leading among Republicans who believe illegal immigration is the most important issue facing the country. However, McCain led among voters who said illegal immigrants should be offered a chance to apply for citizenship and be allowed to stay in the United States. Romney drew strong support among voters who felt illegal immigrants should be deported.

McCain had an edge among voters who said the economy was the top issue and those who felt terrorism was the No. 1 priority. He was leading among those who said the war in Iraq was the top issue.

Other exit poll results revealed that McCain scored well with voters who felt he says what he believes and has the right experience and the best chance of prevailing in November. Romney was leading among voters who said the most important candidate quality was sharing the values of voters.

Romney, a Mormon, excelled among voters from his own church, while McCain drew in the most Catholics and Protestants. Republican Mike Huckabee made one of his best showings among Evangelicals, though McCain prevailed in this category.

Whites accounted for nine in 10 voters in the Republican primary, and that vote was split between the candidates. Hispanics accounted for 6 percent of voters in the Republican primary, and McCain handily won that category.

Also according to the exit polls. McCain had an edge among voters whose family income was $15,000 to $30,000 and $200,000 or more. Romney had an edge among families earning $150,000 to $200,000. McCain appeared to be leading among Catholics, while Romney excelled among Mormons. Mike Huckabee scored well among Evangelicals, though McCain had more support in this category than Huckabee.

Romney held an edge over McCain among voters who had positive feelings about the Bush administration, while McCain was ahead among those with negative feelings about the administration.

On abortion, McCain overpowered Romney among voters who believe abortion should be legal, while Romney held a lead among those who believe abortion should be illegal.

Donald Stallings, a 63-year-old Republican from Phoenix who supported Romney, said McCain was no different than a Democrat.

"I'm not a John McCain fan, and I tend more toward the conservative side of it, although I don't think we have a real conservative that has a possibility of succeeding in there, and I think that Romney probably fits the best with my own leanings," Stallings said.

But retired Air Force Col. Bill Peel, a Republican voter who supported McCain, said the Arizona senator is more conservative than he is given credit for.

"I think he works well with the Democrats," Peel said.

On the Democratic side, Barack Obama held an edge among men, including white men. Hillary Rodham Clinton had an edge among women. Voters 17 to 29 years old were drawn to Obama, while Clinton appeared to be ahead among voters 60 years and older.

She also was ahead among voters 60 years and older.

Obama had a lead among men and an edge among white men. He also won overwhelming support among voters 17 to 29 years old.

Clinton had a slight advantage over Obama among whites, the largest voter group.

Black voters, who accounted for a fraction of those participating in the Democratic primary, overwhelmingly sided with Obama.

Latino voters accounted for nearly a fifth of Democratic voters, and Clinton won that category.

Obama was leading among self-described liberals, while Clinton had an edge among moderates. The two split support among conservatives.

Also in the polling, Obama and Clinton split married men and married women. Obama was ahead among single men, while Clinton was leading among single women.

The two candidates split support among Democrats who said the economy was the most important issue facing the country. They also split the vote among those who said health care mattered the most.

But Obama had an overwhelming lead among voters who said bringing needed change was the most important candidate quality. Clinton overpowered Obama among those who said the right experience was the most important candidate quality.

On gender, Clinton was leading among voters who said the gender of the candidate was important, while those who said it wasn't important sided with Obama. On race, Clinton was leading among voters who said the race of the candidate was important. Clinton and Obama split voters who said race wasn't important in their vote.

Obama had an edge among Democrats who said illegal immigrants should be offered a chance to apply for citizenship and should be allowed to stay in the United States as temporary workers. Clinton was leading among Democrats who said illegal immigrants should be deported.

Eric Heithaus, a 42-year-old guitarist from Tucson, said he voted for Obama because he believes the Illinois senator will end the war. "Of course, human life is the most important thing," Heithaus said.

Gloria Arellano, an administrative assistant from the Phoenix suburb of Ahwatukee, voted for Clinton.

"Obama to me is just a nice guy. I just think people are going to walk all over him like they did Jimmy Carter," Arellano said, noting that she believes the country was in better shape when Clinton's husband was president.

The poll of 1,755 voters was conducted for AP and television networks by Edison Media Research and Mitofsky International.

Results were from interviews of 899 Democratic primary voters and 856 Republican primary voters in 30 precincts across Arizona on Tuesday. Margin of sampling error plus or minus 5 percentage points for each primary. The samples include 304 Democratic voters and 308 Republican voters who voted early or absentee and were surveyed in the past week by telephone.