Republican rationalizations for the party’s dramatic loss Saturday to Democrat Bill Foster in Illinois’s 14th congressional district are almost as weak as their candidate’s showing.

“The one message coming out of 2008 so far,” declared National Republican Congressional Committee (NRCC) spokeswoman Karen Hanretty, “is that what happens today is not a bellwether of what happens this fall.”

Sounds like wishful thinking, Karen.

This was, after all, former Republican House Speaker Dennis Hastert’s district. President George W. Bush defeated John Kerry here by double-digit margins in 2004.

Republicans had a dream candidate in Jim Oberweis, a millionaire ice-cream magnate willing to spend on his own behalf. Ideologically, Oberweis couldn’t have been more representative of the GOP ideal — virulently anti-immigrant, committed to “staying the course” in Iraq and mindlessly repetitive of the “lower taxes” mantra that has driven our nation to record deficits and debt.

Addressing the Foreign Intelligence Surveillance Act (FISA) — an issue Republicans think is a big winner this election — Oberweis blasted Foster hard for refusing to consider retroactive immunity for telecommunication companies: “So today I ask my opponent — if you had been a member of Congress this week, and you had sat in that Democratic Caucus meeting on Wednesday, how would you have voted to instruct your leaders? Would you have sided with the trial lawyers, or with America’s intelligence community? ... Would you have defended the extreme, or the mainstream?”

On FISA, on Iraq, on taxes, on immigration, the wealthy Oberweis fell well within his party’s mainstream. Republican presumptive presidential nominee Sen. John McCain (Ariz.) campaigned on his behalf, as did Hastert himself, who hadn’t had much trouble keeping his district for 20 years.

Oberweis poured $2.3 million of his own money into the race. And the NRCC chipped in another million dollars — or about a third of its meager cash-on-hand.

On the other side, there was a Democrat who — despite running in a tough district —wasn’t afraid to say he was a Democrat. (Foster’s campaign website tagline is, “Businessman. Scientist. Democrat.”)

When Oberweis accused him of “raising the white flag” in Iraq, Foster charged ahead with demands for withdrawal. While Oberweis demonized immigrants, Foster stuck to supporting comprehensive immigration reform with a path to citizenship. And when attacked on FISA, Foster answered clearly and concisely: “The president and his allies in Congress are playing politics with national security, and that’s wrong. Nobody is above the law, and telecom companies who engaged in illegal surveillance should be held accountable, not given retroactive immunity. I flatly oppose giving these companies an out for cooperating with [then-Attorney General] Alberto Gonzales on short-circuiting the FISA courts and the rule of law.”

Rather than attempt to blur the distinctions, as loser Democrats did so often in the past, Foster ran as an unapologetic Democrat and focused heavily on national issues.

The result? The heavily GOP district rewarded the proudly Democratic Foster with a solid, unambiguous victory.

So Karen Hanretty has it backwards. The message of 2008 so far is that no Republican seat is safe this November. A Democratic Congressional Campaign Committee (DCCC) memo detailed the GOP’s dire picture: “[Eighty] percent of the Republican open and Republican incumbent seats the DCCC is targeting this cycle have better Democratic performances than Illinois-14.” That percentage encompasses 40 of the Democrats’ 50 top targets.

Already facing a record number of retirements this year, a few more Republicans may decide it’s best to go out now, while still near the top of their game, rather than be forced into early retirement through inglorious defeat.

Moulitsas is founder and publisher of Daily Kos (www.dailykos.com ).