Perception of Decline

Pew reports:

But while most Americans see the U.S. as the global economic and military leader, many also said the U.S. is not quite as powerful a player on the world stage as it used to be. In a separate survey, nearly half of Americans (46%) said the U.S. plays a less important and powerful role now than a decade ago, compared with 31% who said its role is still as important and 21% who saw it as having increased in importance.
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However, as has been the case since Barack Obama became president, a sizable majority of Republicans (currently 67%) said the U.S. has a less important and powerful role as a world leader than it did a decade ago.

And while this view is particularly widespread among GOP voters who backed Trump in the primaries (77%), most Republican voters who did not support Trump agreed (66%).

Nearly half of independents (48%) and only about a quarter of Democrats (26%) said the U.S. is less powerful and important, and there are no significant differences between Democratic voters who support Hillary Clinton and those who support Bernie Sanders.