Why are we bothering to defend against this type of attack?

The Left has USA Next in its crosshairs, says Michael P. Tremoglie:

The move is on to vilify those who support President Bush's Social Security reform package. The New York Times recently demonized the group USA Next as Republican operatives -- with, gasp, ties to some of the same lobbyists as the Swift Boat Vets. Last week, Lizz Winsted and Rachel Maddow, hosts of Air America radio’s Unfiltered morning program, followed the same template. However, what they omitted said as much about Air America as their demagogic attack. Like the NYT, the leftist hosts tied USA Next to the Swift Boaters (the Left's worst nightmare). According to them, there is a plethora of evil Republican and corporate interests involved with USA Next. They said CEO Charlie Jarvis is linked to the Republican Party and that USA Next is using the same advertising and PR consultants used by the Swiftboat Veterans for Truth. So outraged were Winsted and Maddow that they asked listeners to sign a petition organized by the left-wing group Democracy for America, which will be sent to all the TV stations that dared to broadcast the Swiftboat ads, demanding that these stations deny first amendment rights to USA Next.

The point of the article is a tit-for-tat one: USA Next may have some limited ties to the Republican party, but Democracy for America has strong ties to the Democratic party (and, even more, to Dean). My question, though, is why should we care. If I agree with USA Next's agenda, which I do, why should I care that it has ties to the Republican Party? The fact is that the Republican party also agrees with USA Next's agenda, and is likely to be a source of energetic, connected, well-funded people who can get USA Next off the ground. As long as no campaign laws are being violated, the affiliations shouldn't be important -- the content of the ideas should be. Am I missing something here?