EAST LANSING, Mich. — The Spartans are better than they’ve shown, better than their record. Tom Izzo keeps saying it, and is pretty sure he knows it. So when he sees it, he has two natural reactions. Where has it been? When will we see it again? Oh, it was on display Saturday in Breslin Center, especially in a furious closing flourish. This was Michigan State as it was expected to be, and still can be. Pushed to the brink, the Spartans clamped down on No. 12 Illinois and rallied for an 88-80 victory, one of their most satisfying of the season. Satisfying because the Illini (17-6, 8-4 in Big Te…