The 2012 elections were marked by two major new developments. Anonymous money poured into races on an unprecedented scale. And campaigns used troves of data that people previously considered confidential to “micro-target” voters. Our goal was to shine a light on these tactics, using old-fashioned shoe-leather reporting, public records and innovative computer applications. Throughout the year, our series, “Campaign 2012: Revealing Dark Money and Big Data,” showed readers how groups and campaigns exploited everything from loopholes in federal regulations to Internet surfing habits to win votes.