The first 100 days have been, in some sense, the easy part. President Obama gave stuff to people. Now he's going to have to ask people to give things up.
Domestically, he has primarily accomplished two things: He has succeeded at client politics (i.e. pleased the Democratic base), and he has gotten the federal government to perform demand-side spending (i.e. given things to people). For his efforts, the American people have rewarded him with an approval rating above 60 percent. And Congress has passed a budget resolution that starts to pay for his top priorities.
So far, Obama has been extraordinarily deferential to the legislative branch, drawing only the broadest of outlines and letting powerful liberal committee chairs in the House and centrist committee chairs in the Senate fill in the details. He's tinkered at times, but mostly he's just listened or occasionally cajoled -- acting as a president who respects the balance of power.
Read more of Marc Ambinder's essay, "The 2nd 100 Days," here.