G.O.P. Voters Divided and Embarrassed by Party, Poll Says

© Doug Mills/The New York Times Donald Trump during a news conference at the construction site of the Trump International Hotel at the Old Post Office Building in Washington on Monday.

Alarmed by the harsh attacks and negative tone of their presidential contest, broad majorities of Republican primary voters view their party as divided and a source of embarrassment and think that the campaign is more negative than in the past, according to a New York Times/CBS News national poll released on Monday.

The dismay has not set back their leading candidate, however. While about four in 10 Republican voters disapprove of how Donald J. Trump has handled the violence at some of his rallies, Mr. Trump has also picked up the most support recently as several rivals have left the race. Forty-six percent of primary voters said they would like to see Mr. Trump as the party’s nominee, more than at any point since he declared his candidacy in June. Twenty-six percent favored Senator Ted Cruz of Texas, and 20 percent backed Gov. John Kasich of Ohio.

Fully three-quarters of Republican primary voters expect Mr. Trump to be their party’s nominee

Compared with Republicans, far more Democratic primary voters see their side as unified and say the campaign has made them feel mostly proud of their party.

Yet Democrats are more sharply divided over their candidates. Hillary Clinton has only a slight edge over Senator Bernie Sanders of Vermont, and growing numbers of Democratic primary voters are more excited about Mr. Sanders as their possible nominee. In the past month, the level of enthusiasm for Mrs. Clinton among Democratic voters has fallen eight percentage points to 40 percent, while it has grown for Mr. Sanders by 12 percentage points to 56 percent. Still, more than seven in 10 Democratic voters expect Mrs. Clinton to win the nomination.

Mr. Sanders performs slightly better than Mrs. Clinton in hypothetical general-election matchups against Mr. Trump: The senator beats the real estate developer by 15 percentage points, while Mrs. Clinton prevails by 10 points. Mrs. Clinton holds a narrow edge over Mr. Cruz, while Mr. Kasich is the only Republican who has an advantage over Mrs. Clinton in November.

With the state-by-state nominating contests about half over, Mr. Trump and Mrs. Clinton have pulled solidly ahead of their opponents in delegates. Yet they have also emerged as the cause of the most skepticism and negativity from the electorate nationwide as well as in their own parties.

Half of all voters said they would be scared if Mr. Trump were elected president, and another 19 percent said they would be concerned. Mrs. Clinton does not fare much better: Thirty-five percent of all voters said they would be scared if Mrs. Clinton won in November, and 21 percent said they would be concerned.

Charles Shank, 65, a Kasich supporter, said in a follow-up interview that he was disconcerted by Mr. Trump’s personality and “childish games” and feared that he would not be an effective commander in chief or negotiator with Congress.

“He scares me because he’s a loudmouthed bully,” Mr. Shank said. “He doesn’t come across as presidential. He says ‘I will,’ and I got news for him, he isn’t being elected king. He doesn’t have the ultimate power.”

The nationwide telephone poll was conducted March 17 to 20 on cellphones and landlines with 1,252 adults, of which 1,058 said they were registered voters, including 362 Republican primary voters and 388 Democratic primary voters. The margin of sampling error is plus or minus three percentage points for all adults; four points for all voters; six points for Republican primary voters; and six points for Democratic primary voters.

© Zach Gibson/The New York Times Hillary Clinton in Washington on Monday.

Among Democrats, doubts persist about Mrs. Clinton, with 40 percent of her own party’s primary voters saying she is not honest and trustworthy. She is viewed unfavorably by 52 percent of all voters, among the highest percentage since the question was first asked during the 1992 presidential race.

“I think she’ll say whatever she needs to to get elected, and what she says may not be what she’s planning to do,” said Patricia Lawrence, 55, a Philadelphia Democrat who is supporting Mr. Sanders. “I was concerned already when she was first lady, though I don’t know what it is. I just don’t know, and when we find out, it may be too late.”

Anxieties run higher among Republicans in large part because of the ferocious and at times juvenile nature of the insult-laden campaign, which has featured taunts over character and even manhood as much as serious policy debates. About six in 10 Republican primary voters say the overall tone of their party’s nomination fight has been more negative than in past campaigns, while only one in 10 Democratic primary voters hold the same view of their party’s campaign.

And 60 percent of Republican primary voters said the campaign had made them feel mostly embarrassed about their party, while only 13 percent of Democratic primary voters expressed that opinion.

The potential for political chaos on the Republican side is also intensifying the unease among primary voters. Facing the possibility that no candidate will win enough delegates to clinch the nomination by the end of the primaries in June, two-thirds of Republican voters said it would bad for the party if the nominee were chosen at a contested Republican convention in July.

Mr. Trump’s supporters were particularly apt to say so: Nearly nine in 10 said a contested convention would be bad for the party, far more than Cruz and Kasich supporters.

“The will of the people has been Donald Trump, and if the party won’t support him, they are not supporting the will of the people,” said Bryan Ottalini, 59, a Trump supporter from Stone Mountain, Ga. “I think it would be a definite deal killer for me as far as being a Republican. I would never vote Republican again.”

Mr. Trump has suggested that riots would break out among his supporters if he went into the convention with a solid delegate lead but party leaders denied him the nomination — one in a series of remarks tied to violence that have worried Americans. Sixty-four percent of all voters said they disapproved of how Mr. Trump had handled the physical clashes at some of his rallies.

As for who is to blame for the episodes, 29 percent of all voters blame protesters at the rallies, 23 percent blame Trump supporters, and 43 percent blame both equally.

More than eight in 10 Democratic primary voters have a favorable opinion of their party, but they remain torn over their choices. While Mr. Sanders is regarded as more honest and trustworthy, 78 percent of Democratic voters say Mrs. Clinton’s policy proposals are realistic, compared with 56 percent who regard Mr. Sanders’s proposals as such.

Both parties have work to do with political independents. Seventy percent of them have a negative view of the Republican Party, and 55 percent are critical of the Democratic Party. Mr. Trump, a political outsider, and Mr. Sanders, a self-described democratic socialist who is not a registered Democrat, have performed particularly well among these voters in the primaries so far.