WASHINGTON HEIGHTS : Last week’s presidential inaugural festivities amounted to a fashion gauntlet for GOP revelers, who sported a mix of designer, vintage and off-the-rack gowns and suits. Getting from party to party for most meant slogging through snow and around blocks of city streets closed for security. But once inside, like at Thursday night’s Ford Motor Co. reception at the tranquil Phillips Collection, guests could regroup. Leslie Fahrenkopf, associate counsel to President Bush, arrived at the museum in an off-the-shoulder black Celine cocktail dress and said fashion lovers like herself keep politics out of their wardrobes. Indeed, she opted for a green wool jacket with a taupe pencil skirt designed by loyal Democrat Charles Nolan for the President’s swearing-in ceremony Thursday. Meanwhile, Rebecca Gonzales, wife of attorney general nominee Alberto Gonzales, chose a gold-tone embroidered Carmen Marc Valvo gown for the Phillips reception. “Fashion has always been about individuality,” offered Gonzales of her festive frock.