New Republic has a lengthy article on the lost opportunity of Democrats from 2008 - failing to harness the enthusiasm of President Obama's first victory.
Instead of calling on supporters to launch a voter registration drive or build a network of small donors or back state and local candidates, OFA deployed the campaign’s vast email list to hawk coffee mugs and generate thank-you notes to Democratic members of Congress who backed Obama’s initiatives. As a result, when the political going got rough, much of Obama’s once-mighty army was AWOL. When the fight over Obama’s health care plan was at its peak, OFA was able to drum up only 300,000 phone calls to Congress.
And don't forget all the emails reminding you about birthdays.
Trump and friends thank the Democrats for making this mistake.