President Joe Biden ends nearly every speech by saying he’s “never been more optimistic” about the country’s direction. But lately he's also begun painting a vision of a catastrophic future for the United States, if Donald Trump were to return to the presidency. Biden is accusing the former Republican president of being “determined to destroy American democracy” and being out for “revenge” and “retribution.” There was a time when Trump only merited short and derisive mentions in Biden’s speeches, if Trump drew a mention at all. The change reflects how, with Biden low in the polls, lukewarm Democratic voters might be more motivated by stopping Trump than hearing about investments in infrastructure and renewable energy.