A series of hearings by Senate Majority Leader George J. Mitchell (D-Me.) is more than it seems. Mitchell will hit five cities during the week of Dec. 9-13, ostensibly to solicit views on how the government can ease the health care crisis. But it so happens that the Democratic senators who will chair individual sessions--Wyche Fowler Jr. of Georgia, John Glenn of Ohio, Bob Graham of Florida, and Tim Wirth of Colorado--are up for reelection next year. Each has a fund-raising event scheduled to coincide with the hearing he'll run. Mitchell says the fund-raisers were planned after the hearings and that no health care groups are being asked for contributions. Still, the Democratic Senatorial Campaign Committee is defraying Mitchell's travel costs.