The financial outlook of Americans has sharply improved since early this year amid a spate of generally favorable economic news, according to the Gallup Poll. Consumer optimism now is stronger than at any time since 1976, when the poll began assessing the public’s financial mood. In political terms, the survey said, voters believe that Vice President George Bush would do a better job than Massachusetts Gov. Michael S. Dukakis, 52% to 33%, of keeping the nation prosperous. Since 1960, the political party with a significant lead on this issue in pre-election polls has always won the presidential election. At present, 67% expect to be financially better off a year from now, 17% feel their situation will not change much and 9% predict a downturn. This represents a 9-percentage-point increase in optimism since last January, when 58% thought their finances would improve.