(CNN) - Days after Republicans blasted Michael Steele's "Fire Pelosi!" bus tour as "a colossal waste of time" and "the Michael Steele re-election tour," the Republican National Committee chairman argued that the road trip is playing a crucial role in energizing grassroots activists - even if the bus is spending plenty of time in congressional districts not in play this fall.
"The RNC is all about rebuilding our grassroots, which had been allowed to wither, by tapping into, and helping fuel, the energy generated at the grassroots level," Steele wrote Monday in a list of "talking points" about the bus tour e-mailed to the 168-member committee. The message was forwarded to CNN by a committee member.
Steele said that while the "immediate goal" of the tour is to elect Republicans in November, "it also is to strengthen the party throughout the entire country."
According to an internal copy of the bus tour itinerary provided to CNN last week, nearly half of the stops Steele is making on the cross-country trip are in House districts not listed as "competitive" by top political handicappers.
That schedule drew criticism from Steele's Republican critics, who complained that the committee is wasting precious money on a showy photo-op when it should be sending funds to state parties for voter contact efforts in targeted districts.
The trip's stated goal, according to the RNC's website, is to "regain Congress in 2010 and fire Nancy Pelosi from the office of Speaker of the House." Steele argued, though, that that the tour is not just about electing House members, but also Senators, governors, state legislators and municipal officers.
"The best way to do that, particularly in a midterm election, is to energize as many potential Republican voters as possible, which means going to GOP strongholds as well as marginal districts," Steele wrote in the e-mail, his second "From the Road" dispatch of the trip.
He said that ginning up grassroots energy, even in the Democratic-leaning districts and regions of the country where the bus is visiting, can have far-flung consequences.
"Once generated, voter enthusiasm spreads virally across the country, and is not contained within Congressional districts," he wrote. "The enthusiasm generated by the results of the Alaska Senate primary certainly had a material impact on the results in Delaware."
From the outset of his chairmanship, Steele has promised to re-shape the RNC in order to devote time and resources to regions and constituencies traditionally ignored by the national party, a goal that won him allies among committee members hailing from long-ignored parts of the country.
In his email, Steele cast the bus tour as part of that larger effort. "In the past," he wrote, "the RNC did not even bother to compete in central cities, most of the Northeast, and most inner suburbs, thus conceding huge numbers of seats."
The RNC also neglected traditional GOP strongholds, he wrote, "and lost scores of seats there as well, seats that were even more crucial because of the party's inability to make up those losses in the vast areas of the country where Republicans no longer sought to compete."
"For all those reasons, it is important that the RNC visit a very broad range of communities around the country, not just those that may have a competitive House race this Fall," Steele told the committee.