The National Republican Congressional Committee and conservative third-party groups such as American Crossroads are working feverishly to capitalize on the new opportunities of a rapidly expanding playing field ahead of what is expected to be a good night for the GOP on Tuesday.

As one GOP strategist put it Wednesday, “the more ships we have on the water when the wind is blowing our way, the more that are going to come ashore.”

Both parties are working to determine where the true late-breaking races are.

Today, the NRCC is going up with a television ad in Idaho’s 1st district as well as a radio ad in New York’s 1st district. Those ad buys represent the first independent expenditures that the NRCC has sunk into either district, although the GOP has long talked about targeting both.

The NRCC’s move Wednesday to spend $170,000 against Rep. Ron Kind (D-Wis.) was less expected but not as surprising as a $15,000 media buy against Rep. Chellie Pingree (D-Maine) on Tuesday. Pingree represents a solidly Democratic seat that President Barack Obama carried by 23 points.

Also this week, the well-financed conservative group American Crossroads made $3 million in ad buys in House races, including a few places that have long been considered Democratic strongholds. Among the Democratic-held districts where Americans Crossroads has decided to play are those of Reps. Jim Costa (Calif.), Russ Carnahan (Mo.) and Maurice Hinchey (N.Y.).

“It really doesn’t matter at this point if Republicans are pushing the edge of the envelope in terms of new targets because there’s already very little question about the outcome of this election,” Democratic pollster Alan Secrest said. “There are many individual races still very much up in the air, but the die has been cast in terms of this year’s trend.”

With less than a week to go until Election Day, Republicans are also watching other Democratic-leaning districts, including those of Reps. Dave Loebsack (Iowa), Mike Michaud (Maine) and Solomon Ortiz (Texas), to see whether they become late-breaking races.

Democratic strategists contend that some of the new NRCC spending is defensive and is needed to counteract the flood of Democratic money that is being spent. For example, the spending on Rep. Tim Bishop’s race in New York comes after Democratic groups have been spending heavily to attack the Republican in the race.

“The reality is that Republicans have not closed the door on many of the races that they claim they were targeting,” said Democratic Congressional Campaign Committee spokeswoman Jennifer Crider. “As a result, what they’re doing is throwing more spaghetti against the wall and hoping some of it sticks. Democrats are prepared. They won’t be taken by surprise, and it’s not going to work.”

Democratic surprises on Election Day may be tougher to identify.

“A lot of races that look like victories [for Democrats] will be categorized as a surprise just because of the environment,” Democratic pollster Peter Brodnitz said at a breakfast meeting hosted by Third Way on Wednesday.

But the biggest shockers for Democrats will likely come from Members who pull out victory despite being top targets.

Reps. Tom Perriello (D-Va.) and Frank Kratovil (D-Md.) both won their seats by less than 1 point in 2008 and both began the cycle as top targets. Yet one Republican strategist admitted Wednesday that it’s conceivable that one or both may hang on next week.

Perriello is benefitting from a flood of outside spending that Republicans have been unable to match. Perriello is also getting a visit from Obama on Friday in Charlottesville, a move that campaign strategists said will do more good than harm just days before the elections.

Kratovil is expected to benefit from the upballot gubernatorial race where Gov. Martin O’Malley (D) is favored.

Other possible surprise Democratic victories mentioned by Republican insiders include Reps. Harry Mitchell (Ariz.), Michael Arcuri (N.Y.) and state Sen. Julie Lassa in Wisconsin’s open 7th district seat.

Still, the bigger story coming out of election night will be how successful Republicans were in their effort to capitalize on what has been a huge House playing field.

GOP strategist Chris Perkins said that in some ways Republicans have been more focused on expanding the playing field than reinforcing their top priority races, but that strategy has been successful in forcing Democrats to pull out of several high-profile tossup districts and in turning long shots and bluffs into real opportunities.

The NRCC will “start a fire, and the question is do the Democrats come in and put it out. If they don’t put it out, it can manifest into a true pickup opportunity.”

Perkins argued that’s what happened in recent weeks to 10-term Rep. Gene Taylor (D-Miss.), who is now in a serious race against state Rep. Steven Palazzo (R).

Taylor, who suddenly found himself the target of NRCC attacks in mid-October, has since seen more than $300,000 in NRCC funds pour into his district. The DCCC has yet to spend a dime through its IE in the district.

Brodnitz acknowledged Wednesday that a major challenge for Democrats in the final weeks of the campaign has been to determine which Republican moves were “sneak attacks” against truly vulnerable incumbents and which moves were simply “throwing names out to get us to spread our money out.”

This late in the game, it’s probably unrealistic to expect the field to expand any more, Perkins said.

“There aren’t any more complete and total sleepers,” he said.

But one GOP source with knowledge of the NRCC ad buy strategy said Wednesday that the expansion process may not be over just yet.

“If we get more money, we’ll be adding points this weekend to other races,” the source said. “And if the election were two weeks from now, we would have kept spreading fires because the money would have kept coming in.”