Donald Trump’s electoral gains paradoxically offer Democrats a glimmer of hope in the next few elections, according to a new analysis. The former president picked up wins in urban, suburban and rural counties and improved on his vote share in 49 of the 50 states, with improvements in 90 percent of all U.S. counties. But a new CNN analysis suggests the magnitude of those gains is the result of a factor that might work against Republicans next time. “The scale of Trump’s advance this year points toward a common national experience in all regions of the country — a shared disappointment in the re…