Sen. Hillary Rodham Clinton of New York, addressing the media at her national headquarters in Arlington, Va., yesterday, has the support of many Rhode Island Democratic leaders.

AP / Carolyn Kaster

PROVIDENCE — A month ago, New York Sen. Hillary Rodham Clinton appeared to have a lock on Rhode Island’s Democratic presidential primary.

And why not? If ever a presidential couple lavished attention on a state that in a generation has never mattered in presidential selection, it was Bill and Hillary Clinton, who visited Rhode Island on numerous occasions both during and after his presidency.

But now, the close and intense Democratic race between Clinton and Illinois Sen. Barack Obama has made the state’s March 4 presidential primary a potentially crucial event on the path to winning the nomination.

Both campaigns will be scratching for every delegate vote; Rhode Island’s affection for the Clintons is about to get its severest test.

“They are known here; Bill Clinton was very popular and well-received here and Hillary Clinton has been here many, many times,” said Bill Lynch, Democratic state chairman. “With Senator Obama, the momentum he has seized throughout the country is going to be reflected in some measure here.”

Obama also campaigned in Rhode Island twice in 2006 for Sheldon Whitehouse’s victorious U.S. Senate campaign, even driving here once at the last minute from New Jersey when his flight was grounded by fog, said Lynch.

Among Republicans, the March 4 test has boiled down to a joust between Arizona Sen. John McCain and former Massachusetts Gov. Mitt Romney. McCain easily won the Rhode Island GOP presidential primary in 2000, the year he lost the nomination to then-Texas Gov. George W. Bush. McCain has won GOP primaries in New Hampshire and Connecticut.

Romney won his home state of Massachusetts but has not done well in other New England contests, with the exception of the Maine caucuses, which he won. Governor Carcieri is Romney’s biggest boldface name supporter in the state.

The GOP delegate arithmetic heavily favors McCain, who established himself as the clear Republican front-runner on Tuesday. Rhode Island House Minority Leader Robert Watson, R-East Greenwich, has been a McCain supporter and campaign organizer since 1999. Watson is optimistic he can persuade McCain to hold a campaign event in Rhode Island. “I’m hopeful we’ll get a piece of him,” he said.

Mike Huckabee, the former Arkansas governor popular with evangelical Christians, is also on the state GOP ballot, but his candidacy so far has drawn scant traction in states where the religious culture is dominated by Roman Catholics and mainline Protestants. Ron Paul, the libertarian Texan, is also on the state ballot.

“Super-Duper” Tuesday is over, but there is no rest for the candidates. Democrats have 10 contests between now and March 4.

They start on Saturday with a primary in Louisiana and caucuses in Nebraska and Washington. The U.S. Virgin Islands also has a contest Saturday. Then on Sunday, Maine holds its caucus. The Obama campaign has asked U.S. Rep. Patrick Kennedy to campaign for the Illinois senator this weekend in the Pine Tree State, Kennedy said yesterday.

Next Tuesday are the Potomac primaries: Maryland, Virginia and the District of Columbia.

On Feb. 19, Hawaii holds a Democratic caucus, and Wisconsin holds a primary.

On March 4, Rhode Islanders get to vote in Democratic and Republican primaries the same day as Ohio, Texas and Vermont. Ohio has 161 delegates; Texas, 228. Rhode Island has 32 Democratic delegates and Vermont awards 23.

In a race where the candidates, particularly on the Democratic side, are fighting for every vote, “Vermont and Rhode Island will be in play that day,” says Garrison Nelson, a University of Vermont political science professor.

“Voters in both states will see the candidates; it might just be a flyby and an airport rally, but they will visit,” says Nelson. “This hasn’t happened in recent elections because the nominees were usually chosen by the time the calendar hit March.”

Hillary Clinton has the endorsement of the political heavyweights, including Senator Whitehouse, U.S. Rep. James Langevin, Lt. Gov. Elizabeth Roberts, state General Treasurer Frank Caprio, Providence Mayor David N. Cicilline and House Speaker William Murphy. Her name recognition among loyal Democrats approaches 100 percent.

Kennedy is one of the few major Democrats supporting Obama. But what the Obama forces lack in endorsements, his supporters believe they can make up in momentum and youthful enthusiasm. Obama has hired Mike Dorsey, the organizational maven who engineered the voter turnout campaign for the state Democratic Party in 2006, which vaulted Whitehouse to victory in his Senate race over then-Republican incumbent Lincoln Chafee.

And Obama has drawn young people willing to uproot their lives and do the grunt work of identifying voters and driving them to the polls. They are activists like Dave Stuebe, a 27-year-old oceanographer, who is getting door-to-door voter canvasses set up in Rhode Island.

“I’m all in, this is really an important moment in this country’s history,” Stuebe said.

The Obama campaign’s youthful enthusiasm was on display Tuesday evening at the Local 121 restaurant on Washington Street in downtown Providence, where about 80 Obama fans greeted each state victory flashed on a huge television screen with beer-fueled cheers.

Organized labor, for the most part, has stayed neutral in the Obama-Clinton clash, said George Nee, secretary-treasurer of the Rhode Island AFL-CIO. One Rhode Island influential union that has endorsed Clinton is the Rhode Island Federation of Teachers, the powerful union that represents public school teachers in urban districts.

Democratic Sen. Jack Reed, the state’s senior senator, has stayed neutral and does not expect to make an endorsement before March 4.

Bill Clinton and his wife came to the state more than a dozen times while he held the White House; the state’s Democratic voters returned the favor, rolling up big margins for Clinton in his 1992 and 1996 presidential victories.

Bill Clinton raised money at Mark and Susan Weiner’s house in East Greenwich, stumped for Myrth York in Providence, noshed on Block Island with Reed and boosted Kennedy at the Portuguese Social Club in Pawtucket. He and his wife bowed their heads at Sen. John Chafee’s funeral at Grace Church in Providence.

Clinton came to the state so often he once joked that he ought to pay taxes here.

Now Hillary Clinton may find herself in a tight contest against Obama, a contest that nobody predicted a month ago.

Delegates are awarded in both parties by complicated formulas. On the Democratic side, 13 delegates and three alternate delegates will be elected on March 4 in each of the state’s two congressional districts — 7 from the second district and 6 from the first. The delegates will be awarded to candidates based on the proportion of the vote each receives. Three alternate delegates will also be chosen primary day.

Five at-large delegates will be apportioned according to primary results. Three delegate slots are reserved for party leaders and elected officials; these seats usually go to legislative leaders. There is also one add-on delegate elected at the June 19 Democratic State Convention. The rest of the delegate seats are held by so-called super delegates and include top party and Democratic elected officials, such as Reed, Whitehouse, Kennedy, Langevin, Lynch, AFL-CIO president Frank Montanaro, Mayor Cicilline and others elected by the state committee.

Republicans in Rhode Island have a total of 20 delegates; 17 delegates and 17 alternates will be selected based on the primary results March 4, according to the secretary of state’s office.

“We’ve never seen anything like this before in New England, where primaries that aren’t held in New Hampshire matter,” says Nelson, the UVM professor. “This one should be interesting.”

marsenau@projo.com