We live in a dangerous world. There is always at least one major power which does more than wish us ill, but actually acts to our detriment. At the moment that "enemy" group would include China and, to a lesser extent, Russia. I won't dignify Iran by calling it a "major power" but they regularly call for our death. So, in opposition one major power, one almost major power, and one regional power. And then there are the non-state actors like the various jihadi terrorist groups.
You wouldn't have known any of the above by watching the recent Democrat convention. The need to counter threats from abroad - a major federal responsibility - went almost entirely unmentioned.
We also face threats at home from Antifa and Black Lives Matter rioters and looters. Their threats to residents and businesses the almost universally Democrat mayors of large cities seem unwilling to confront.
Again, you would have believed no urban problem existed if you based your opinion on watching the recent Democrat convention. The obvious need to preserve and insure domestic tranquility was on none of the participants' minds.
The only danger most Democrats could see on the horizon is President Trump. He is certainly a danger to the aspirations of Democrat politicians, but has he been a danger to you? I'd argue for most law-abiding citizens the answer is a clear "No."
To the extent to which fending off antagonistic foreign powers and jailing domestic law breakers are goals to which most Americans subscribe, to that extent the Democrats failed to respond to the electorate's felt needs, to your felt needs. Please allow their disinterest to inform your choice of representatives when your vote this fall for the House, the Senate, and the Presidency.