Iowa Laggards Biden, Warren Shift Ad Spending to Stay in Race

(Bloomberg) -- Elizabeth Warren and Joe Biden are shifting ad spending in early voting states as they fight to re-energize their presidential bids following poor showings in Iowa.At the same time, Iowa’s surprise delegate leader Pete Buttigieg is bulking up his spending, buying ad time in places he hadn’t expected to compete in hopes of a strong showing in New Hampshire.It’s not unusual for candidates to shift resources shortly after an election, either to capitalize on a stron