The Democrats’ efforts to convince their own voters that Joe Biden is still capable of leading the nation highlight a troubling disconnect from the public. When a party has to work this hard to reassure its base, it’s a clear sign that something is fundamentally wrong with their strategy. This struggle will only intensify as the Democratic Convention approaches and Biden's candidacy becomes official. If convincing their own ranks is this challenging, the general election campaign promises to be even more brutal for Biden.