Donald Trump and Bernie Sanders Gain Credibility, While Rivals Scramble

Presidential candidates awoke on Wednesday morning and set their sights on South Carolina and beyond while still absorbing the results from a New Hampshire primary election that added credibility to the surprisingly powerful movements behind Donald J. Trump and Senator Bernie Sandersof Vermont.

Both the Democratic and Republican results largely reflected polling predictions in New Hampshire, though the magnitude of Mr. Sanders’s victory leaves him with more momentum than anticipated as he heads to some potentially tougher contests. The tight race for second place on the Republican side, with a pack of candidates trailing Mr. Trump, has left that battle more muddled than before.

But Tuesday’s voting had some immediate ripples in thinning the field of Republicans. After a sixth-place finish in New Hampshire, Gov. Chris Christie of New Jersey has told allies that he plans to suspend his campaign, according to two people briefed on his intentions, and is meeting with his staff on Wednesday to discuss the decision. And Carly Fiorina, the former head of Hewlett-Packard, announced that she was suspending her campaign after coming in seventh.

The remaining candidates were grappling with how to frame the next phase of the campaign as many of them headed to South Carolina for rallies. While Republicans mulled new ways to slow Mr. Trump, Hillary Clinton’s campaign continued to face questions about how she could lose by nearly 22 percentage points to Mr. Sanders, a 74-year-old socialist. Mr. Sanders, hoping to improve his standing with African-Americans, traveled to New York City and met with the Rev. Al Sharpton.

Two days after spewing a profanity at a campaign event in New Hampshire, Mr. Trump struck a more presidential tone. In an interview with NBC, he said that his opponents were all impressive and accomplished people and hinted that he would temper his bombastic behavior as the nomination nears.