A lack of competitive open-seat House races in 2010 could complicate Republican efforts to fully maximize a favorable national environment and make large seat gains after back-to-back elections where the political winds were blowing in the opposite direction.

So far, 18 Members have announced they are not seeking re-election in 2010 and are running for other office instead — but only six of those races are currently considered competitive. No Member has yet announced an outright retirement, which is unusual; at this point in the 2008 cycle, 14 Members had announced their retirement and five others were running for Senate.

The number of Members vacating seats in 2010 is certainly much lower than it was in 1994 — when Republicans last won control of the House from Democrats in the first midterm election of a Democratic administration. Next year, comeback-minded Republicans are confident the party will gain seats after big losses in the 2006 and 2008 elections, and they are hoping political elements will come together to produce a wave similar to 1994.

Rep. Kevin McCarthy (Calif.), who heads candidate recruitment efforts for the National Republican Congressional Committee, acknowledged the low number of open House seats, but he said the 2010 elections won’t be kind to Democratic incumbents.

“I believe this is an anti-incumbent year. … Where the majority has been taking people is not one that the country is supporting,— McCarthy said.

But with few House Democrats making this Congress their last, Republicans will need to defeat as many incumbents as they can if they want to win back the majority or at least make significant gains. In November 1994, the GOP defeated 34 House Democratic incumbents — much more than the net gain of 18 that the party made in open-seat races. The GOP hasn’t defeated more than five Democratic incumbents in any election cycle since.

Former Rep. Tom Davis (Va.), who won the first of seven terms in 1994 and later headed the NRCC, wrote in U.S. News & World Report on Nov. 6 that “unlike in 1994, few vulnerable Democratic seats are currently open heading into the midterms.—

There are compelling reasons that explain the lower-than-average number of retirements. Barring a political catastrophe, House Democrats will still hold a majority in 2011, and they’ll be able to work at least two more years with a Democratic White House.

Asked why House Democrats have few retirements this cycle, Democratic Congressional Campaign Committee Chairman Chris Van Hollen (Md.) said, “The Democrats just regained the majority in 2006, and Democratic Members of Congress are excited by the fact that we now have a Democratic president that we can work with to enact a new agenda for America.—

It’s also understandable that there will be fewer retirements this cycle than in the 2012 cycle, when Congressional boundaries will be redrawn and some Members will retire rather than run in significantly altered districts.

In the 2008 cycle, House Republicans were badly hurt by retirements on their side. Of the 32 Members who decided not to seek re-election — either to leave political life or to run for some other office — 26 were Republicans and just six were Democrats.

In the November elections, Republicans lost a dozen of their open seats and didn’t win a single Democratic open seat. By comparison, 14 GOP and five Democratic incumbents were defeated for re-election.

In 2010, Republicans are defending 12 of the 18 open seats, and only three of those are currently competitive.

The toughest open seat for Republicans to hold is the one Rep. Mike Castle (Del.) is giving up to run for Senate. Democrats are also high on their chances of picking up the suburban seats being vacated by Reps. Mark Kirk (Ill.) and Jim Gerlach (Pa.), who are leaving to run for Senate and governor, respectively.

“You have a number of significant Republican retirements — not a huge number, but in districts that present good pickup opportunities for the Democrats,— Van Hollen said.

The best opportunity for a GOP pickup in an open-seat race is in Louisiana’s 3rd district, a conservative-leaning area in the southeastern part of the state that Rep. Charlie Melancon (D) is giving up to run for Senate. Louisiana has been trending Republican, and Sen. John McCain (R-Ariz.) carried the 3rd with 61 percent in the 2008 election.

The GOP is also targeting two other Democratic-held districts, where Reps. Joe Sestak (Pa.) and Paul Hodes (N.H.) are running for Senate.

Both districts gave Obama 56 percent of the vote in the 2008 election, but Republicans are touting the fact that they have recruited top candidates in each race.

In Pennsylvania, the presumptive Republican nominee is Pat Meehan, a former U.S. attorney. In New Hampshire, former Rep. Charles Bass (R) is running to reclaim the seat he held for six terms before losing to Hodes in 2006.

“You look at what has transpired in these open seats already — good, good movement in there,— McCarthy said.

There will be more retirements in the 2010 cycle, and the bulk of them almost certainly will be announced within the next two or three months. In the 2008 cycle, 16 of the 32 House Members who said they would not seek re-election made those plans public within one year of the November 2008 elections, with 12 of them saying so in November or December 2007 or in January 2008.