Amid the tumult of several good elections for Democrats, including the 2006 tide that sank all Republican boats, three GOP members of Congress have held on to otherwise Democratic seats by narrow margins. This year, as a perfect storm looks set to sweep GOP incumbents from office coast to coast, the three survivors look likely to swim, or sink, together.

Though U.S. Reps. Dave Reichert, Mark Kirk and Christopher Shays represent districts about as far apart as one can get without crossing an ocean, they have remarkably similar constituencies. Voters they represent are largely well-educated, well-off and, as their survival demonstrates, willing to split tickets between popular politicians of both parties.

Should the three decide to form some sort of support group, Shays would be the grizzled veteran. Having represented Connecticut's 4th Congressional District for 21 years, the moderate Republican has recently found himself squarely in Democratic sights as his Greenwich- and Stamford-based district trends more towards Democrats. Though Shays easily won re-election during most of his tenure, he beat a well-funded Democratic opponent by four points in 2004 and just three points -- 7,000 votes -- in 2006.

Kirk may be younger, but while Shays has faced easy elections, the Illinois Republican is a veteran of more nail-biters. His similarly affluent district along Lake Michigan just north of Chicago has been hard-hit by the downturn in the economy, and two years after Kirk staved off voter anger over the war in Iraq he now finds himself defending an economic front. Kirk faces a rematch of his 2006 race against Democrat Dan Seals, who he beat by six points that year.

Reichert is the new guy who's already seen it all, seeking his third term in Washington's 8th Congressional District, just across Lake Washington from Seattle, perhaps the most liberal metropolis in the country. Though the district has traditionally Republican exurbs closer to Mt. Rainier in the south, Reichert's survival still depends on moderates who largely choose Democrats in other races.

The incumbents have three things in common: They represent suburban districts, all three of which voted for both Al Gore and John Kerry over President Bush; have records that could serve as the definition of middle of the road; and recent polls have shown all three tied with or trailing their Democratic opponents with just a week to go before Election Day.

To understand why the Republicans have survived so far, and why they find themselves in such difficult positions right now, is to realize just why Republicans are in so much trouble nationwide.

Shays, Kirk and Reichert all represent historically Republican districts that are nonetheless trending Democratic. And yet they keep their seats, strategists agree, because of finely-honed constituent communication and voter outreach programs. Those programs, campaign strategists say, demonstrate each member's personal popularity in his own district. "You can't do [major field programs] unless you have lots of volunteers and lots of supporters in your own district," said Mike Shields, Reichert's chief political aide.

"We have no illusions about the task ahead," said Chris Healy, chairman of the Connecticut Republican Party, about Shays' race. Shays' field operation is "infinitely superior" to other Republicans in Connecticut, he said, "because it has to be."

Too, each of the three are closely attuned to districts in which constituent relations matter. Shays and Kirk were two of the only vulnerable members of Congress to vote in favor of the first version of the economic bailout bill, though given their districts' affluence, that was probably the right vote politically. Reichert is a former King County sheriff, and he can't introduce himself to a crowd without reminding them he caught one of the most infamous serial killers in American history; for younger families who move to the suburban district in order find a safe place for their children to grow up, that's a recipe for electoral success.

Finally, all three incumbents have strong individual brands in their districts. Residents in Connecticut, Illinois and Washington know they are represented by Shays, Kirk and Reichert, all of whom are better defined than the average member of Congress might be in their own district. Despite living in districts that will likely give a majority of their votes to Democrat Barack Obama, all three incumbents have won recently as Democrats higher on the ballot have carried the seat.

"Republicans haven't won the Tenth Congressional District at a presidential level probably since Reagan. We've always won at the congressional level because we happen to elect members who are really independent," said Illinois GOP Chairman Andy McKenna, who has known Kirk since before Kirk first won election. "Many Obama voters will vote for Mark Kirk because they believe a Republican member of Congress will bring a good check and balance" (Obama is beating John McCain in Kirk's district 54 percent-39 percent, according to a recent poll).

But none of that has completely insulated any of the three from facing tough challenges. Shays is tied with local Democratic activist Jim Himes, according to a recent University of Connecticut poll, at 45 percent apiece. A poll by the independent firm Research 2000 take for the DailyKos shows Reichert and former Microsoft employee Darcy Burner tied at 46 percent each. Another Research 2000/DailyKos poll shows Kirk trailing his 2006 opponent, advertising executive Dan Seals, by a 49 percent-43 percent margin.

This year, voters may not care for good constituent services and an ear to the ground. Even if all three incumbents run perfect campaigns, the simple fact of an "R" after their names may be enough to doom them.

If three candidates with such strong brands are still swamped in a wave election, that bodes ill for members of the GOP who have taken less time to prepare for their own re-elections and for candidates running for open seats. Shays, Kirk and Reichert are far from what their constituents would describe as a generic Republican, and if they can't survive this year, more generic GOPers won't either.

Should the moderate suburbanites lose this year, there will be implications within the Republican conference, no matter how small it is after next week's losses. Already, at least ten moderate Republicans are not seeking re-election this year, and Democrats have a strong chance of picking up all but one -- only Rep. Ray LaHood's seat is a virtual lock to be held by the GOP. The dwindling number of Republican moderates, a group that ruled the party just a few decades ago, could force the GOP farther to the right.

In short, if Shays, Kirk and Reichert don't make it to the 111th Congress, Republicans will have a very bad night. The loss of well-defined members would indicate a climate in which more generic Republicans will fall far more easily. And the loss of three well-known moderates would move the Congressional GOP just that much more to the right. That could end up delaying, rather than hastening, the GOP's ascent back to power.

Reid Wilson, national columnist for Politicker.com, is also an associate editor of RealClearPolitics.com and covers Senate, House and governors' races at PoliticsNation.com.