AP Photo/Reba Saldanha
- Former President Trump's robust showing on Super Tuesday led to Nikki Haley ending her campaign.
- But there were warning signs for Trump in the results, as he faltered in populous suburbs in N.C. and Va.
- Many suburban voters began drifting away from the GOP in 2016, costing the party critical seats in recent cycles.
Former President Donald Trump had a commanding victory on Super Tuesday, winning 14 of the 15 states that held a Republican primary or caucus.