MANCHESTER, N.H. — Senator Bernie Sanders of Vermont won New Hampshire’s Democratic presidential primary Tuesday night, consolidating support on the left in his second strong showing in as many weeks.

Mr. Sanders fended off two moderate rivals, former Mayor Pete Buttigieg of South Bend, Ind., and Senator Amy Klobuchar of Minnesota. Senator Elizabeth Warren of Massachusetts and former Vice President Joseph R. Biden Jr. finished behind them.

Only a small fraction of the total available delegates have been awarded in the Democratic primary so far. So what do Tuesday night’s results mean for the race going forward? Read on.

Bernie Sanders is the front-runner of a muddled race.

Mr. Sanders won the most votes in Iowa, even if he narrowly lost the delegate battle. He won the New Hampshire primary. His support among people of color has grown in polls, while his chief competitor for those voters, Mr. Biden, has been fading in the overall contest. He has climbed to the lead in some national polls. And he is raising more money — and has more money — than any of his rivals who are not billionaires.