Bush-Cheney campaign manager Ken Mehlman and other senior Republican strategists say the volunteer army that swept President Bush to re-election this month is poised to deliver increasing margins of control to the GOP in both chambers of Congress, beginning with the elections of 2006.

Karl Rove, the architect of Bush’s victory, and other GOP strategists acknowledge daunting historical and structural challenges ahead — including the tendency for a second-term White House to lose seats in its sixth year and the fact that redistricting has made the “playing field” of competitive House seats far smaller than ever before.

But senior Republican officials believe, on the basis of the 2004 results, that the party has developed a corps of roughly 1.4 million party stalwarts who have proved they can offset traditional Democratic advantages at the grassroots level.

The Republican confidence is based on a bold wager: that the volunteers went to work to support the Republican agenda — not just President Bush.

“It wasn’t just a cult of personality that you saw in the campaign,” Mehlman said in a pre-Thanksgiving interview. President Bush “said, ‘Vote for me because I will do these things …,’ and people went to the polls and voted for him.”

Rove has pointed out that the president increased his vote total in 45 of 50 states between 2000 and 2004, with the largest percentage gains being made in states where he actually lost, such as New Jersey, Hawaii and Rhode Island.

“You have the opportunity and the fixings there to institutionalize this truly awesome volunteer infrastructure,” one top GOP strategist said.

The strategist noted that in 2004, the Democrats had met every conceivable turnout goal they set, yet “the Republicans just leap-frogged them.”

Mehlman, who is slated to take over the chairmanship of the Republican National Committee in January, is expected to work hand-in-glove with GOP Congressional officials to mobilize the newly assembled volunteer corps on behalf of House and Senate candidates.

One top GOP strategist in the House said the Republicans are already poring over data from the 2004 vote, searching for new opportunities. The key, the strategist said, will be to first identify areas where Bush won the popular vote but the party’s Congressional candidates fell short.

“What we’ve got to figure out basically is, why did Bush get that voter? Is there one issue that made the voter support Bush even though he voted for a Democrat in the House?” the strategist said.

Rove has indicated that his ultimate goal — one that lies beyond Bush’s political success — is to build a “permanent” Republican majority. Rove has cited the model established in 1896 by Mark Hanna, an Ohio pragmatist who built a winning coalition for William McKinley by appealing to immigrant populations in the Midwest and Northeast and bolstered further by urban Democrats who feared union violence that was common at the time.

It worked: The 1896 election ushered in a period of Republican dominance that endured until the Great Depression.

Already, preliminary analyses have shown a sharp advantage building for the Republicans in “exurbs” — fast-growing communities located beyond more established, and now often Democratic-leaning, suburbs. These exurbs are attracting young, married professionals who lean Republican.

A post-election examination by the Los Angeles Times showed that Bush won 97 of the 100 fastest-growing counties in the country. Republican strategists believe these urban exiles are responding positively to Bush’s “ownership society” message, which includes sweeping changes to Social Security and tax policy.

In the meantime, the volunteer corps has added a new dimension to the Republican ground game that will see its first battlefield test over the next two years.

Rove and I “have in common the belief that we can continue to grow a majority in the House and Senate that will keep us in the majority for many years to come,” said Rep. Tom Reynolds (N.Y.), who is starting his second term as chairman of the National Republican Congressional Committee.

“Karl’s vision has been a permanent Republican majority,” said one top GOP strategist who is close to Rove. “They’re very close now structurally to having the capability to [solidify the majority] for a very long time.”

Brian Jones, who serves as a spokesman for the Bush-Cheney campaign and for Mehlman, said that the incoming chairman intends to focus on expanding the party and ensuring that the gains from 2004 — which included pick-ups in both the House and Senate — are “durable.”

“In order for it to be a true [Republican] trend, we have to transfer and build on it by increasing the majority in the 2006 elections,” Jones said.

Jones acknowledged that success will depend to a degree on whether the grassroots enthusiasm for Bush himself can be transferred to the wider Republican Party.

“That’s the case we need to begin to make,” Jones said.

GOP strategists believe that the grassroots operation’s voluntary nature was perhaps the biggest key to its success. Rove figured volunteers would be more effective than paid campaign workers because they’re “true believers” and would be better at convincing neighbors and friends to follow their lead.

The RNC’s success in building the volunteer base enabled the Bush-Cheney campaign to focus on building a message that could keep the grassroots engaged and determined.

Congressional Republicans are cognizant of the key role they will have to play if the successes of the 2004 cycle are to be repeated. Party strategists are working to structure the agenda of the 109th Congress to ensure that the volunteer army is carefully nurtured over the next two years.

“It seems to me that if we’re going to do the permanent majority that Karl is talking about, you not only need the right issues, you need to keep your people motivated,” a senior GOP strategist said.

At a post-election lunch with reporters, Rove downplayed some of the more exuberant projections that are taking hold among some Capitol Hill Republicans.

He pointed to the role redistricting has played in lessening the competitiveness of House races. And Rove suggested that it was unlikely that the GOP hopes of a filibuster-proof 60-seat majority in the Senate could be achieved any time soon.

“But then,” he added, “I didn’t think we would get to 55.”