(The Wall Street Journal) Pity Joe Biden. He has to convince voters both that the economy was booming less than three years ago when he and Barack Obama were in charge and that its now fallen into such a mess that we need Mr. Biden to come fix it. Whereas Ronald Reagan beat Jimmy Carter in large part by asking voters to consider if they were better off than they were four years ago Mr. Biden and the seemingly endless list of other candidates running for president would rather voters think about anything but the economy. Democrats want American voters for the next year and a half to be perpetually anxious that the end is imminent but can be staved off at the ballot box. This is nothing new. Politicians like to warn voters that the current election is the most important one in their lifetimes. Though politiciansand some used car salesmencan be forgiven for their over-the-top sales antics many candidates actually believe their elections are critical to the fate of the republic and that their opponents must lose for humanity to continue flourishing. Republicans who persistently remind voters of the unique virtues of the Founding Fathers and the limited government they created nonetheless constantly warn that the next Democrats election threatens to undo centuries of sacrifice. Invoking a historic sense of urgency isnt limited to election cycles. Progressives seem to be in a constant state of frenzy about the crisis of the hour. Without a moment to celebrate the decline of mass starvation and extreme poverty they turned their attention to rising child obesity and income inequality. The decline in smog and air pollution coincided with a new focus on rising CO2 emissions. Global cooling was seamlessly replaced with the existential threat of global warming. The Supreme Court decision striking down state bans on gay marriage was immediately succeeded by legal wrangling over transgender rights pronoun usage and bathroom access as the next great civil-rights fight.