This is just the tip of the iceberg. To maintain their Senate majority in 2014, Democrats need to hold onto seven seats being contested on inhospitable turf–Louisiana, Arkansas, Alaska, Montana, West Virginia, North Carolina, and South Dakota. Obama holds solid approval ratings nationally but, given the state of affairs in our polarized country, is in much more tenuous shape down South. The strategic positioning of Democratic Sens. Mary Landrieu of Louisiana, Mark Pryor or Arkansas, Kay Hagan of North Carolina, and Mark Begich of Alaska will be fascinating to watch over the next year. Immigration, for example, is probably a winning issue for the president overall, but it will be a much tougher sell with Democrats in conservative states and districts. Rockefeller took the easy way out in stepping down.

My National Journal colleagues Ron Fournier and Jill Lawrence have been engaging in a debate over whether Obama is merely a good president, or a potentially great one. I disagree with the premise. I’d argue that given Democratic congressional supermajorities in his first two years and the lingering unpopularity of the Republican Party, he held the potential to accomplish a lot more–and in a more bipartisan fashion, as well. Health care reform was a costly detour from promoting a jobs-centric agenda in the president’s first year. He’s spending significant political capital on Hagel, at a time when the White House desperately needs a united Democratic front on gun control and immigration.

Obama’s predecessor, George W. Bush, learned the hard way about bragging about his mandate, seeing his own ambitious Social Security reforms blow up in his face thanks to recalcitrant Republicans, and watching his approval ratings trend downward from there. Understanding the political limits, while also recognizing strategic opportunities, is an essential part of a president’s job responsibility.