Nov. 30 (Bloomberg) -- Republican presidential contenders are shredding Ronald Reagan's ``11th Commandment'' call for party decorum, and acting more like feuding Democrats of yore.

The candidates are engaging in escalating personal attacks on each other, turning policy debates into angry exchanges and questioning their foes' veracity. And given the wide-open nature of the race for the nomination, ``things will get worse -- before they get really nasty,'' said Republican strategist John Feehery, who isn't affiliated with any 2008 campaign.

The Republicans' Nov. 28 debate in St. Petersburg, Florida, ``was a circular firing squad,'' said Democratic strategist Chris Lehane. ``One clear winner emerged: the Democrats.''

Reagan's 11th Commandment -- ``Thou shall not speak ill of any fellow Republican'' -- was little in evidence. Former Massachusetts Governor Mitt Romney, 60, and former New York Mayor Rudy Giuliani, 63, flayed each other for hypocrisy over immigration, with Giuliani accusing his rival of employing illegal aliens in a ``sanctuary mansion'' and Romney replying that closer scrutiny of his foreign workers would be un- American.

Former Tennessee Senator Fred Thompson, 65, used his time for a promotional ad to air a video assailing the credibility of Romney and former Arkansas Governor Mike Huckabee, 52. And Arizona Senator John McCain, 71, tore into Romney for backing torture because he refused to disavow water-boarding, a controversial prisoner-interrogation technique.

`Personal Animosity'

``You're seeing a level of personal animosity that you have not seen on the Republican side to date,'' said party consultant Scott Reed, who managed Senator Bob Dole's 1996 presidential bid. ``You've got a front-loaded calendar and you have a number of strategies that are not coming together for some of these campaigns. You're also seeing some desperation, from exhaustion and from just plain old being scared.''

While Democrats are doing their own sniping -- Illinois Senator Barack Obama suggests frontrunner Hillary Clinton shades the truth, and Clinton, a New York senator, says Obama is too inexperienced to lead the nation -- most of their thrusts have been tame by comparison.

Neither Obama, 46, nor Clinton, 60, has so far shown much zest for the sort of sustained brass-knuckle campaigning that marked previous Democratic nomination struggles. Obama, in a new Time magazine cover story, has this to say about Clinton: ``It's perfectly legitimate for her to suggest that I don't have enough experience to be president.''

`Tough Guys'

Ken Khachigian, a California-based Republican strategist and former Reagan aide, said the sharper tone in his party's contest in part reflects the personalities of the candidates. ``You've got a lot of tough guys up there with big egos,'' he said. ``A lot of them are not used to being attacked the way they are, so they all feel they have to get very edgy to break through.''

Romney, who seeks to deliver a crippling blow to Giuliani in the Jan. 8 New Hampshire primary, accuses the former New York mayor of falling into a pattern of manufacturing statistics about things such as Romney's crime record as governor of Massachusetts.

Thompson, who appeared recently on Fox News to plug his tax plan, veered off into an attack on the network's commentators, whom he said were trying to sabotage his campaign by emphasizing the futility of his late-starting bid.

`Club for Greed'

It isn't just the candidates who are doing the attacking. The Club for Growth, a group that backs candidates -- usually Republicans -- who favor limited government, is going after former Arkansas Governor Mike Huckabee. The group has issued campaign broadsides and run independent TV ads in Iowa, site of the first presidential caucuses on Jan. 3, depicting Huckabee as a Big Government tax-raiser. Huckabee has taken to calling the organization ``the Club for Greed.''

Khachigian says the rough-and-tumble tone of the primary campaign may not prove to be such a bad thing if it toughens the eventual nominee for the general-election battle against the Democrats. ``At the end of the day you'd like to have your president to have gone through a lot of fire to get there,'' he said. Besides, ``even President Reagan broke the 11th Commandment a few times.''

To contact the reporter on this story: Edwin Chen in Washington at echen32@bloomberg.net.

Last Updated: November 30, 2007 00:15 EST