Democratic House and Senate candidates could be heading into November’s general election with a built-in, top-of-the-ticket advantage if voter-turnout statistics from the Iowa and New Hampshire presidential nominating contests are any indication of things to come.

Significantly more Democrats than Republicans showed up for the Jan. 3 Iowa caucuses and the Jan. 8 New Hampshire primaries, with Democrats enjoying a 2-1 turnout advantage in the Hawkeye State and a nearly 51,000-vote edge in the Granite State. The Democratic turnout numbers in both states included heavy participation by independent voters, who were given the option of which party to vote with.

With a solid advantage in aggregate fundraising for Democratic presidential contenders over the past year compared with their GOP counterparts ($241.1 million to $175.1 million), political strategists now are forecasting that Republican Congressional candidates could have even more more hurdles to overcome than they originally thought.

“This clearly shows that the energy and enthusiasm are in support of the Democratic candidates,” Democratic Congressional Campaign Committee Chairman Chris Van Hollen (Md.) said in an interview. “The Democratic candidates have been able to capture the mood and imagination of the country, and that will help our [Congressional] candidates.”

Republican House and Senate candidates already were juggling several potentially fatal political daggers — among them Iraq, President Bush’s low approval ratings, generic ballot deficiencies and a pronounced fundraising advantage by the two Democratic Congressional campaign committees.

Now they face the prosect of being dragged down at the polls on Nov. 5 by a combination of low GOP turnout, high enthusiasm among Democrats for their White House nominee and an independent vote that favors the Democrats.

Both parties face uncertain and potentially bloody battles for their White House nominations in the weeks ahead, and the dynamic of the general election could largely be determined by the outcome of these fights.

On the Democratic side, Sens. Barack Obama (Ill.) and Hillary Rodham Clinton (N.Y.) are the frontrunners, though former Sen. John Edwards (N.C.) still is a factor. On the Republican side, four or even five candidates remain in the hunt for the nomination.

But regardless of whom the parties nominate, enthusiasm for now seems higher on the Democratic side — and that energy could be felt up and down the ballot in November.

“The idea that coattails means something is undeniable,” Democratic strategist Tom Lindenfeld said. “It is a true part of the political calculus in any year.”

GOP consultant Dave Gilliard recalled how, in one House race, lackluster Republican turnout in the 1996 general election helped transform a lead in the polls for California Superior Court Judge Linda Wilde (R) into a 996-vote loss to incumbent Rep. George Brown (D-Calif.). President Bill Clinton beat former Sen. Bob Dole (R-Kan.) by 8 points nationally that year, but topped him by a whopping 13 points in California.

Republican strategists, though worried, caution that it is too soon to apply the results of Iowa and New Hampshire to the upcoming general election. Particularly in Iowa, a swing state that supported the Democratic presidential nominee in 2000 and Bush in 2004, the numbers were striking, as 239,000 voters participated in the Democratic caucus, compared with just 118,696 who voted in the Republican caucus.

“It’s too early to forecast what will happen in November, and it would be a mistake to read too much into these primary results and the current state of mind of GOP voters” said Gilliard, who is based in Sacramento, Calif., and whose client roster includes House candidates. “When both parties have a [presidential] nominee and voters are faced with two very different candidates, visions and platforms, the November campaign will take on its own dynamic.”

Republicans propelled themselves to victory in several targeted House and Senate races in 2002 and 2004 partly on the strength of the independent vote. However, that trend came to a halt in 2006, as the GOP lost both the race for unaffiliated voters and control of both chambers of Congress.

If polls measuring how independents voted in Iowa and New Hampshire are a sign of how voters will behave in this year’s Congressional elections, Republican House and Senate candidates could be in for another rocky cycle.

According to entrance polls of Iowa caucus voters and exit polls of New Hampshire primary voters conducted by CNN, the Democratic presidential candidates won the battle for independents. In Iowa, 20 percent of Democratic caucus voters described themselves as “independent,” while only 13 percent of GOP caucus voters did the same.

In New Hampshire, Democrats trumped Republicans on two exit-poll questions related to independent voters. Forty-two percent of voters who participated in the Democratic primary described themselves as “registered independents,” while just 34 percent of “registered independents” participated in the GOP primary.

With regard to “party identification,” 44 percent of voters who participated in the Democratic primary described themselves as “independent,” while just 37 percent of voters participating in the GOP primary described themselves similarly.

“This tells us that honestly, that, if trends continue, the excitement on the Democratic side, the independents coming home and becoming part of the Democratic Party is great news for Democrats and troubling at best for Republicans,” said Democratic strategist John Lapp, who worked as a top consultant on the DCCC’s payroll last cycle and still advises House candidates.

Republicans, though aware of the potential danger for their down-ticket candidates, argue that there also are signs that bode well for them.

The situation in Iraq appears less dire, and Bush will be replaced as the leader of the GOP once the party’s presidential nominee is chosen — and with the president increasingly in the rearview mirror, his low job-approval numbers will hurt Republican Congressional candidates less and less, according to the argument made by many strategists working for the various GOP House and Senate candidates.

Republicans also expect the GOP base to rally around the Republican presidential nominee and turn out for GOP candidates, once it becomes clear that either Obama or Clinton could be the next president.

In Obama’s case, Republicans claim his record is too liberal for most Americans, and they contend that GOP voters and like-minded independents will recoil once the Illinois Senator faces the scrutiny that comes with being the Democratic presidential nominee. In Clinton’s case, Republicans contend that GOP voters will flock to the polls just to vote against her no matter who becomes the party’s presidential nominee.

Republican Congressional strategists actually are hoping to face Clinton, believing her high personal negatives will benefit GOP House and Senate candidates on Election Day.

On the fundraising front, the Republican National Committee had $15.7 million in cash on hand at the end of November, compared with just $2.8 million for the Democratic National Committee. That money will be used to help the GOP presidential turnout operation, which in turn is expected by Republican strategists to aid their House and Senate candidates.

The DCCC and Democratic Senatorial Campaign Committee maintain healthy cash leads over the National Republican Congressional Committee and the National Republican Senatorial Committee, respectively.

“Neither the Iowa caucuses nor the New Hampshire primary can realistically be used as models to somehow forecast what turnout might look like at the national level next fall,” NRCC spokesman Ken Spain said. “Republicans will rally behind our presidential nominee and will have plenty of incentive to turn out with the likelihood of a flawed Democratic nominee.”