The metaphor of a marathon doesn’t capture the wearisome, confounding, terrifying and yet somehow dull and drab nature of this ordeal for many Americans, who have watched leaders fumble the pandemic response from the start. Marathons have a defined conclusion, but 2020 feels like an endless slog — uphill, in mud. Recent opinion polls hint at the deepening despair. A Gallup survey in mid-July showed 73 percent of adults viewed the pandemic as growing worse — the highest level of pessimism recorded since Gallup began tracking that assessment in early April. Another Gallup Poll, published Aug. 4, found only 13 percent of adults are satisfied with the way things are going overall in the country, the lowest in nine years. A July Kaiser Family Foundation poll echoed that, finding that a majority of adults think the worst is yet to come. Fifty-three percent said the crisis has harmed their mental health.