In April, Obama's numbers returned to a normal level, after experiencing a very short post-election "honeymoon period" with the public which bounced his numbers up to a peak, and then bounced them right back down again.
Filibustering has been a major problem in the US Senate for several years. The tactic is causing obstruction in Congress, and the problem will continue to exist if the United States remains as partisan as it is now.
President Obama had a fairly flat month in the polls. His approval rating slipped back half a point, and his disapproval rating stayed unchanged from last month. While his approval stayed above his disapproval for the month, the gap between the two is smaller than it's ever been.