Updated

It's the dirty secret of this year's midterm election cycle: that many of the congressional seats so hotly contested this fall won't even exist when the 2012 cycle rolls around.

That's because the current cycle is unfolding concurrently with the federal government's completion of the Census, the massive effort to count everyone in America that takes place every 10 years and which is always followed by a reordering of the congressional map.

Based on population shifts over the last decade, some states will see their number of seats in the House of Representatives increase, while others will lose a seat or more. It will then fall to the 50 state legislatures in 2011 to redraw the boundary lines of each of their state's existing congressional districts - a process known as redistricting.

Since 39 governors are statutorily empowered to play some role in that process - with some even wielding veto power over it - the battle for gubernatorial seats in the 2010 midterm cycle takes on added importance. And as that battle moves into its final month, with activists needing to be energized, donors needing to be pumped for cash, and voters needing to be swayed, both parties are seeking to project optimism.

"The DGA is on offense and we plan to win," declared Gov. Jack Markell (Del.), chair of the Democratic Governors Association. Speaking to reporters at the National Press Club on Tuesday, Markell disputed widespread predictions that the Republicans will seize the majority of governors' mansions. The edge in this category is presently held by the Democrats, by a margin of 26 to 23 (Gov. Charlie Crist of Florida, seeking to become the state's senator, recently changed his party affiliation from Republican to independent).

"The postmortems of this election were already written this summer, before the voters even engaged," Markell said. "But the voters are paying attention now. And the movement towards Democrats that we're seeing is a result of both of that engagement and the electorate's desire to reward results."

However, a number of independent political handicappers see the trend lines moving against the Democrats. The website realclearpolitics.com projects that Republicans by year's end will control at least 28 governorships, with Democrats holding onto 15, and another eight currently listed as toss-ups.

"I'd be disappointed if we didn't get to at least 30," Gov. Haley Barbour (Miss.), chair of the Republican Governors Association, told Fox News. "California is a very close race, where [Republican and former eBay executive] Meg Whitman leads [Democratic Attorney General Jerry Brown] by a point or two, then trails by a point or two....If you take Pennsylvania, Ohio, Michigan, Wisconsin, Illinois, Iowa -- they all have Democratic governors today. And in every one, either the Republican is ahead or the race is too close to call."

Democratic candidates nationwide are benefiting from massive campaign contributions from public-sector labor unions, even as the Republicans depend heavily on corporate donations, like the $1 million that News Corp., the parent company of Fox News, recently gave the RGA. "We'll put more into these races in October than we spent in all of 2006," Markell said.

Some analysts see the particular results of this year's Census, in which the nation's population could shift to the south and west, heightening pressure on Democrats to stem the party's projected gubernatorial losses. "The states losing seats and electoral votes will be predominantly Democratic ones like New York and Massachusetts," said Fox News digital political editor Chris Stirewalt. "Losing control of the redistricting process right now would have dire consequences when it comes to future elections."