All American Girl - Meg Cabot
Sam lives in Washington DC, is the middle teenager between two very annoying sisters, and dyes all her clothes black. She has a best friend, she's not cool like her big sister, she doesn't have a boyfriend but thinks she's in love with someone, and she likes to draw. Her credentials as an "ordinary" girl who thinks she's a misfit (black clothes, not a cheerleader) are established immediately, and the story flies from there. Sam's appeal lies in how she's bothered about making things genuine in her life, whilst Cabot's winning touch is in her realism--the president is a normal guy who likes cookies; the plot where Sam saves him is not impossible; the resulting fuss is boring and her priorities lie elsewhere (making lists of Top Tens, worrying about who she wants to go out with, going to her drawing classes).