THE NATION: 6 Ways to Watch the Election; State Capitols as Weather Vanes "Call them canary states. If you want a measure of the vote on election night -- and whether the results qualify as an upheaval or just a tremor -- the state legislatures in PENNSYLVANIA, OHIO, MICHIGAN and WISCONSIN are the places to watch. They're all Republican redoubts in states with mixed political climates, and all have Democrats pounding at the gates. ''If you see Democrats take charge in any one of those eight chambers, it's a sure sign that it's been a red-letter night for Democrats,'' said Tim Storey, a senior fellow at the National Conference of State Legislatures. Incumbency, redistricting and large majorities on the Republican side all work against the Democrats' hopes of tilting the balance. But the Pennsylvania House of Representatives, which has 109 Republicans and 94 Democrats, is the one considered closest to Democrats' grasp. The House has been under Republican control since 2002, and redistricting from the 2000 census solidified many of the majority-held seats. Local lawmakers in Pennsylvania have faced public antipathy over a generous pay raise that they voted for themselves late last year. The raise was rescinded after a public outcry just before the campaign season began. KIRK JOHNSON"