The challengers advantage

The incumbent has "Name Recognition" & is one of the main benifits in the run for re-election.

In politics, the challenger is often said to have great disadvantages compared with the incumbent. Under the current situation in the US, however, the challenger has only to say that the incumbent did it wrong, and I would have done it right. His alternate plan, which has not been tested in the real world, would work while the incumbents real life plan had flaws and shortcomings.
Seems to me that you need a very closely split and divided electorate for this strategy to bear fruit. Is there any other evidence of this approach succeeding in a democracy?