Into the Politics of Economics WASHINGTON FEW people try to get the attention of the president of the United States by tugging on the bottom of his suit jacket until he looks their way. But Peter Mankiw had an important message to deliver, and he was not going to let diplomatic procedure, or the president's personal space, get in the way. So, after President Bush had sworn in Peter's father, Gregory, as the new chairman of the Council of Economic Advisers last month, Peter, who is 4 years old, made a run for the presidential coat. "Don't be mean to...