Among the major candidates seeking the GOP Presidential nomination, former Tennessee Senator Fred Thompson is viewed as politically conservative by more voters than anybody else. That’s true among all voters and also among Republican voters. It’s a key factor in why Thompson is currently doing so well in the race for the Republican Presidential nomination.

Thompson and former Arkansas Governor Mike Huckabee are the only candidates seen as more conservative in this survey than before.

Perceptions of former Massachusetts Governor Mitt Romney and former New York City Mayor Rudy Giuliani have changed little over the past month. Arizona Senator John McCain is less likely to be considered politically conservative than he was a month ago.

Among Republicans, 49% now see Thompson as conservative (up from 42% a month ago). Forty percent (40%) say the same about Romney (little changed from 39% a month ago).

McCain is now viewed as politically conservative by 31% of Republican voters. That’s down ten points from 41% a month ago. It’s worth noting that McCain and Thompson were virtually tied on this question among Republican a month ago. Now, there is an 18-percentage point gap between them.

Twenty-nine percent (29%) of Republicans view Huckabee as politically conservative, but 39% don’t know enough to venture an opinion one way or the other.

Rudy Giuliani, the frontrunner in the polls for most of the year, is viewed as politically conservative by just 20% of Republican voters. Sixty-four percent (64%) of the GOP faithful view him as politically moderate while 9% say he’s liberal. As he seeks the Republican nomination, Giuliani has to hope that his personal popularity can overcome concerns about his political leanings.

Thompson, Romney, and Huckabee are more likely to be seen as politically conservative by Republican voters than other voters. The opposite is true for Giuliaini and McCain.

Among all voters, Thompson is viewed as politically conservative by 44% of all voters. That’s up from 37% in May and 32% in April. Just 21% consider Thompson politically moderate while 6% see him as liberal. Twenty-nine percent (29%) don’t know enough to have an opinion.

For Romney, the latest numbers are 41% conservative, 27% moderate, and 6% liberal. A month ago, 40% viewed him as politically conservative.

McCain has had a tough month of June as public attention has focused on the immigration debate. He has lost ground in the race for the Republican nomination, his favorables are down, and he is now a weaker performer in match-ups with against Democrats such as New York Senator Hillary Clinton. Not surprisingly, given the debate over immigration, the number seeing McCain as politically conservative has fallen to 38% from 45% a month ago.

Giuliani is seen as politically conservative by just 23% of voters. That’s down from 25% a month ago and 28% the month before.

Huckabee is less well known than the other candidates—49% don’t know enough to have an opinion as to his ideology. Overall, 25% view him as conservative, 18% say he’s moderate, and 6% perceive him as politically liberal.