While the filibuster is more flashy, I think the most powerful tool at any congresscritter's disposal is simply to deny the use of uninimous consent. Every single time a motion is made for unanimous consent, object. the legislative process will quickly grind to an absolute halt. It forces complete roll calls for every single vote. Makes them actually read the bills on the floor (2 times if I recall correctly). It's also not strenuous or taxing on any individual. If you have 3 or 4 folks willing to play the game, that's all it takes to enforce it on every single measure, no matter how small.
Thanks for reminding me. Forgot about that rule. My point was that
McConnell has had still has numerous tools(rules) at his disposal
and has chosen not to use them to stop Obama.