From the Danged If You Do, Danged If You Don’t Hopper: Democratic U.S. Sen. Blanche Lincoln of Arkansas probably is the most vulnerable Senate incumbent for a number of reasons, led by the fact Republican John McCain carried “The Natural State” by nearly 20 points in 2008. Add in Lincoln’s vote for Obamacare in December and it’s not hard to see why most of the state Republicans vying to oppose her in November lead in individual matchups. How bad is Lincoln’s situation? The word around Washington was that while Lincoln, a moderate, was key to health care’s passage, her re-elect numbers were so poor the White House and Democratic leaders didn’t bother trying to buy her vote like Ben Nelson’s (“Cornhusker Kickback”) and Mary Landrieu’s (“Louisiana Purchase”). Now Lincoln has a problem on her left flank. Arkansas Lt. Gov. Bill Halter says he’ll oppose her in the Democratic primary. That puts Sen. Lincoln in a real box on health care. If she opposes it the next time around she might not survive the Democratic primary; if she votes for it again she’s toast in the general election.