Not long ago, House Minority Leader Nancy Pelosi (D-Calif.) boasted to a meeting of the Democratic National Committee that Democrats would win back the House and Senate in 2006 and elect the first woman Speaker. Pelosi’s prediction may have drawn cheers from the partisan crowd; but after the November elections, she is more likely to find herself trying to explain another election loss to her colleagues than measuring the Speaker’s office for new drapes.

To win back the House, Pelosi and company will have to overcome what amounts to a 10-year advantage provided to Republicans by the post-2000 Census redistricting process. The 2004 redistricting effort in Texas, which gave Republicans five more seats, was icing on the cake and effectively put Democratic control of the House out of reach for the rest of the decade.

Sure, it’s theoretically possible for Democrats to win back the majority, but so is winning the lottery. Neither is likely to happen.

In truth, Pelosi has already missed the boat. It sailed after the last census, when Republicans won the redistricting wars and subsequently picked up eight seats in 2002. Barring a political catastrophe, that victory has likely put the majority out of reach for the Democrats until 2012, following the next redistricting.

Democrats will dispute that assertion, but the history of the redistricting process doesn’t support their argument. In 1980, it was the Democrats who held an advantage in the redistricting process with solid control of a majority of state legislatures and governorships; and they knew how to use that advantage.

The best example was California’s famed 1980 redistricting plan, drawn by then-Democratic Rep. Phil Burton, which trounced Republican chances of any meaningful gains. When asked about what was one of the most contorted Congressional maps drawn that year, Burton joked, “It’s my contribution to modern art.” In 1982, Democrats gained 26 seats. Even with the Reagan landslide of 1984, Republicans were able to pick up only 14 seats. Over the next three elections, they lost 16 seats.

Ten years later, however, the political environment had changed somewhat, and for those of us drawing lines (I was involved in the last three end-of-decade redistrictings through the Republican National Committee), it was a new day. Republicans had made modest gains in legislative seats and governorships, but it was another factor that dramatically changed the redistricting landscape, particularly in the South.

For decades, minority political strength had been diluted through redistricting to achieve bigger Democratic victories, but at the expense of their own African-American and Hispanic candidates. In 1982, Congress amended the Voting Rights Act to give minorities the opportunity to elect candidates of their choice.

The effect, however, was to destabilize Democrat seats at both the state legislative and Congressional level, giving Republicans the first opportunity for real gains in a decade. Under the new rules, Democrats could no longer create majority-Democrat districts by distributing minority voters into as many Congressional seats as possible.

At the same time, great strides in information technology gave those of us drawing the lines in 1990 the ability to target voting behavior and demographic attributes with increasing specificity. As minority districts were created, neighboring districts became competitive for the first time in a long time, and Republicans finally had the shot they were looking for to make real gains.

For example, in Georgia in 1990 there were nine Democratic Members of Congress (one was African-American) and one Republican. By 1994, there were four Democratic Members (three were African-American) and seven Republicans.

Although President George H.W. Bush’s weak showing in the 1992 election cost the party Congressional seats, with Republicans managing only a 10-seat pickup, redistricting put the party in position to win. Two years later, Republicans retook the House with a 52-seat gain.

Leading up to 2000, Republicans had made big gains in statehouses and state legislatures across the country thanks to the post-1990 lines. Population shifts to the West and South also gave Republicans an advantage. Any hope of the Democrats retaking the House in 2002 faded as Republicans solidified their majorities through the 2000 redistricting process and won eight more seats.

Both Republicans and Democrats also had access to remarkably improved technology over the previous redistricting. While most redistricting data was still found on mainframes in 1980, by 2000, I was able to put all the demographic and election redistricting data for four states on one laptop and draw lines anywhere.

Moreover, the technology had reached such a level of sophistication that districts could be drawn with incredible specificity to all but ensure political outcomes. Regardless of both parties’ relatively equal access to technology, the party controlling the process inevitably gains the advantage.

Maryland’s redistricting is a case in point. There, Democrats controlled redistricting and were able to add just enough voters to ensure Republican Rep. Connie Morella’s defeat.

Increasingly sophisticated redistricting technology has done something else. It has created, through precision line drawing, districts that provide, de facto, 10-year terms for incumbents of both parties. Unlike the Senate, where we see some turnover, today 90 percent of both Democratic and Republican Members of Congress find themselves in safe seats. For them, the biggest challenge they are likely to face is from within their own party — a primary challenge, not a tough general election battle.

For incumbents of either party, that’s a good place to be, although it has saddled Congress with a certain ideological inelasticity as most Members, Democrat or Republican, tend to be less centrist and more attuned to their base. Compromise is made more difficult as re-election becomes easier.

Just as earlier redistricting tipped the scales for Democrats in the 1980s and then for Republicans in the 1990s and in 2000, the outcome of the 2010 redistricting will likely determine control of Congress for the next decade.

While it’s possible Democrats may pick up a handful of seats in 2006, with only 10 percent of the seats in play, they are unlikely to gain enough to drive Republicans from power any time soon. Their next real election opportunity is still seven years away — 2012.

David Winston is president of The Winston Group, a Republican polling firm.