President Obama's challenge in taking on Wall Street is not unlike a similar challenge that was faced by President Theodore Roosevelt just over a century ago, write Simon Johnson and James Kwak. They say that Obama must go "all in" for financial reform. "Will the administration stand up and fight now, before we have another crisis?" they ask. "Surely this is what Theodore Roosevelt would have done. He liked to act preemptively; when he saw excessive power, he took it on, creating his own moments of political opportunity."