http://www.newsweek.com/id/71000/page/1 I've seen up close the two Clintons America knows. He's a big smile, hand locked on your arm and lots of charms. "Hey, come down and speak at my library. I'd like to talk some politics with you." And her? She tends to be, well, hard and brittle. I inherited her West Wing office. Shortly after the 2001 Inauguration, I made a little talk saying I appreciated having the office because it had the only full-length vanity mirror in the West Wing, which gave me a chance to improve my rumpled appearance. The senator from New York confronted me shortly after and pointedly said she hadn't put the mirror there. I hadn't said she did, just that the mirror was there. So a few weeks later, in another talk, I repeated the story about the mirror. And shortly thereafter, the junior senator saw me and, again, without a hint of humor or light in her voice, icily said she'd heard I'd repeated the story of the mirror and she … did … not … put … that mirror in the office. It is a small but telling story: she is tough, persistent and forgets nothing. Those are some of the reasons she is so formidable as a contender, and why Republicans who think she would be easy to beat are wrong. The Republican presidential nomination is the most fluid and unpredictable contest in decades, but the Democratic nominee is likely to be Hillary. Not without a fight, not without losing early contests (probably Iowa, for starters) and not without bruises and bumps. And so the question to John McCain from a woman at a town hall in South Carolina last Monday was tasteless, but key: "How do we beat the [rhymes with witch]?" Right now, Republicans are focusing much of their fire on Senator Clinton. Criticizing her unites the party, stirs up the unsettled feelings many swing voters have toward her and allows each candidate to say why he is best able to beat her. For now, that's enough. But when a GOP nominee emerges, he needs to remember no Republican is as well known as Hillary. The Republican has room to grow in the polls as voters get a better sense of who he is and what animates him. Here's what he needs to do.