As the cadre of Illinois Senate candidates barnstormed the state in the final weekend of campaigning before today’s primaries, both parties’ frontrunners cemented double-digit leads in a race that only one month ago prognosticators predicted would go down to the wire.

Polling in the race in the past week has shown state Sen. Barack Obama (D) and investment banker-turned-teacher Jack Ryan (R) well out in front in their equally crowded primary fields.

Still seeking to overtake Obama, the first black editor of the Harvard Law Review, are state Comptroller Dan Hynes and millionaire securities trader Blair Hull, the only other candidates in double digits according to the latest poll conducted in the race. Cook County Treasurer Maria Pappas and former Chicago School Board Chairman Gery Chico round out the top contenders in the seven-way Democratic race.

As the campaign’s focus turned to field operations in the last 48 hours, Obama’s campaign is getting a boost from an estimated 12 people from Philadelphia Mayor John Street’s (D) campaign who have descended on the Windy City for the final push. The campaign is also renting audio equipment and other field operation relics stored since Street’s re-election victory last fall.

Meanwhile, with snow falling in Chicago late Monday afternoon and weather forecasts calling for wind chills below freezing Tuesday, weather could also be an important factor in today’s turnout.

To help volunteers braving the inclement weather, Obama’s campaign has ordered 3,000 ponchos emblazoned with “Obama for Senate.”

Although polls show the state Senator with a healthy lead, depressed turnout in Chicago and its surrounding suburbs could be a boon to Hynes, who has staked his campaign on the Democratic organization’s ability to get out the vote.

Hynes has the backing of the state’s AFL-CIO, as well as many of the party establishment’s heavy hitters.

As St. Patrick’s Day festivities and party dinners took center stage for candidates crisscrossing the state over the weekend, a Mason-Dixon poll published Sunday showed Obama with 37 percent, while Hynes and Hull were in a statistical dead heat for second place, with 18 percent and 16 percent, respectively.

In the final weekend of campaigning, friction heated up between Hull and Hynes, both of whom have concentrated their efforts on winning a large percentage of the downstate vote. That area of the state is largely credited with propelling now-Gov. Rod Blagojevich (D) past two primary opponents in the 2002 gubernatorial race, when he won large margins there despite being from Chicago.

In the only spat to hit television airwaves during the campaign, an attack ad produced by Hull’s campaign was aired accidentally by a Springfield TV station on Friday. The ad, targeting Hynes, prompted the comptroller to air a counterattack on Hull, criticizing him for his negative spot.

Hull has charged that both Hynes and Obama are beholden to special interests through their acceptance of campaign contributions, and on Saturday, Hull campaign literature targeting Hynes on that front was placed on cars parked near the St. Patrick’s Day parade in Rockford.

Hynes, who hails from a heavily Irish-Catholic neighborhood in Chicago, attended both the Rockford and downtown Chicago St. Patrick’s Day parades. Sunday he worked the South Side Irish Parade, in the city’s 19th ward, where his father, Tom Hynes, is committeeman.

Obama, who has concentrated his efforts in Chicago and surrounding areas, spent Sunday rallying his base at black churches in the city before embarking on a rare downstate swing to Peoria and East St. Louis. He also began airing TV ads featuring the image of the late Harold Washington, Chicago’s first black mayor.

Meanwhile, Hull campaigned at several Catholic churches in Chicago, a low-key approach for the one-time frontrunner. Hull poured more than $29 million of his personal fortune into the race before seeing his poll numbers plummet in the wake of allegations he physically and verbally abused his now ex-wife while the couple was in the midst of their second divorce. While Hull was hurt substantially in the Chicago media market, it still remains unclear how much of his support has eroded downstate.

On the Republican side, Ryan appears to have successfully staved off nagging questions about the sealed portions of his 1999 divorce records for now, even as his opponents continued over the weekend to call for him to clear the air on the matter.

Still, the number of undecided voters remains high among Republicans, a sign that the race is likely to be much closer than polling predicts, and all of the candidates appeared to be spending their final hours campaigning downstate.

The Mason-Dixon poll over the weekend, showed Ryan with 45 percent of the vote, with millionaire paper company executive Andy McKenna and dairy magnate Jim Oberweis in a dead heat at 12 percent and 11 percent, respectively. State Sen. Steve Rauschenberger (R), who has a good deal of institutional party support, was at 7 percent.

As the leading GOP candidates campaigned at a Lincoln Day dinner downstate Saturday, Oberweis called on Ryan to release the sealed divorce records to an independent third party.

Oberweis suggested Ryan show the documents to Illinois GOP Chairwoman Judy Baar Topinka, former Gov. Jim Edgar or Cardinal Francis George of Chicago, so that they can report to voters on whether they contain material that should be an issue in the race. Topinka has already offered to look at the files, but Ryan rejected the idea.

Ryan has maintained that the files, part of the couple’s custody dispute, were sealed and need to remain sealed to protect their now-9-year-old son.

Meanwhile, with the Senate race taking top billing in the state, there is little to no activity in House primaries across the Land of Lincoln.

In the one primary of note, former Rep. Mel Reynolds (D) is attempting a comeback bid in the South Side Chicago 2nd district seat he was forced to resign in 1995. Rep. Jesse Jackson Jr. (D) was elected to replace Reynolds, who resigned amid charges of having sexual relations with an underage campaign worker.

He was later convicted of campaign fraud, obstruction of justice and criminal sexual assault and served five years in prison before being granted clemency by then-President Bill Clinton in early 2001.

Reynolds, 52, charges that Jackson is detached from the district and is unresponsive to the needs of constituents back home.

Jackson, meanwhile, contends that his arch political rival, Dolton Mayor William Shaw, is behind Reynolds’ candidacy. With little evidence that Reynolds’ bid has legs, the 39-year-old lawmaker has paid little attention to Reynolds, who has almost no campaign organization and has not filed paperwork with the Federal Election Commission.

Jackson had $704,000 in cash at his disposal as of Feb. 25.

Still, Jackson, who is co-chairing Obama’s Senate campaign with Rep. Danny Davis (D-Ill.), got some fundraising help this weekend from former Democratic presidential contender Howard Dean this week (see story, page 16).

Also running in the primary against Jackson are the Rev. Anthony Williams, a social activist who has run for Congress once before, and former Chicago police officer Everett Shumpert.

Davis faces his own primary challenge Tuesday, from defense attorney Anita Rivkin-Carothers and gallery owner Robert Dallas.

Although his re-election appears virtually assured, Davis charges that his political rival, 29th ward Alderman and Committeeman Ike Carothers, is behind his aunt’s challenge to the Congressman. Carothers ousted Davis as 29th ward Democratic committeeman in 2001.