Exactly. Sidious DID try to blow the hell out of Mace. However, a minor complication arose in the formof Windu's lightsaber. Dunno what movie you were watching, but in the theatrical release of revenge of the sith, Mace not only blocked the lightning with his saber, but redirected it back into Sidious' face. It took Anakin disarming Mace to allow for the opening the Palpatine needed. It was blatantly obvious.