CEDAR RAPIDS, Iowa — Joe Biden and Elizabeth Warren, two of the leading candidates for the 2020 Democratic nomination, made the case on Monday for muscular new gun control proposals, but differed on whether it was possible to reach compromise with congressional Republicans.
Mr. Biden said it was not. Ms. Warren seemed more open to the idea.
As much of the Democratic field fanned out across Iowa and New Hampshire to campaign this holiday weekend, Mr. Biden told reporters in Cedar Rapids, Iowa, that the only solution for major new gun control legislation was to defeat Republicans in the elections 14 months away — “flat-out beat them,” as he put it.
Mr. Biden, the former vice president, has made bipartisanship a theme of his campaign and has talked about working with Republicans, including Senator Mitch McConnell. But Mr. Biden took an unequivocal stand on expanded background checks and other measures when asked if there was room to reach a compromise with Mr. McConnell, the Senate majority leader, on legislation following the nation’s latest spate of mass shootings that left 53 dead in August.
“None, none on this. I think this is no compromise. This is one we have to just push and push and push and push and push,” he said. “The fact of the matter is, I think this is going to end with some of them defeated.”
Ms. Warren, the Massachusetts senator, has taken more aggressively liberal positions than Mr. Biden on health care, student debt and other domestic issues, and she is generally more critical of Republican Party leaders (while he tends to focus on President Trump). On gun control, she has endorsed a range of measures, but she espoused a different view from Mr. Biden when asked if she could see a compromise with Republicans that fell short of expanding background checks.
“Could they agree to do some things and not that one? Look, that’s part of what making legislation is all about,” Ms. Warren said in Hampton Falls, N.H. “What we need to do is what’s effective to bring down deaths from gun violence.”
Ms. Warren argued that the issue needed to be addressed in a broader way, not just with a single legislative fix. She reiterated the ambitious goal she had included in the gun violence plan she laid out last month: to reduce overall gun deaths, not just those from mass shootings, by 80 percent, along the lines of how the country has reduced automobile deaths over the past half-century.
“We need to treat this as the public health emergency that it is,” she told reporters. “And it’s going to take a lot of pieces and a lot of changes that we need to do to bring down deaths from gun violence. And that needs to be our goal.”
Mr. Biden and Ms. Warren — who will meet for their first debate on Sept. 12 after being on separate debate stages in June and July — were among several Democratic presidential candidates who championed gun control measures over the Labor Day weekend in the aftermath of the fatal shootings on Saturday in Midland and Odessa, Tex.
At a town hall-style meeting in Peterborough, N.H., Senator Bernie Sanders called for background checks as well as a new assault weapons ban, and argued that most Americans support greater gun control measures — but their views are being countered by the influence of the National Rifle Association.
“We are telling Trump and McConnell, listen to the American people and not the N.R.A.,” Mr. Sanders said.
Mayor Pete Buttigieg of South Bend, Ind., who was campaigning in Cedar Rapids on Monday, said background checks were already “a very middle-of-the-road, rather conservative compromise.” He signaled that Democrats needed to stand firm on proposals for background checks, which are expected to be part of a gun control debate in Washington following the mass shootings in El Paso, Midland and Odessa, and in Dayton, Ohio.
“We’ve got to get out of a defensive crouch,” Mr. Buttigieg said of Democrats. “The overwhelming majority of the American people are with us, and the congressional G.O.P. can only reject the American people’s desires for so long before they’re going to pay a political penalty for that.
“We’ve got to get something real out of this,” he said.
Senator Amy Klobuchar of Minnesota, who, like Mr. Biden and Mr. Buttigieg, holds a mix of progressive and moderate views, said background checks were “the minimum that we should do.”
“Then we should go to something that will make the biggest difference for the mass shootings,” such as a new assault weapons ban, she said.
With their remarks, the Democrats were seeking to add more pressure to Mr. Trump, who indicated openness to background checks after the El Paso and Dayton shootings, and to Mr. McConnell, who has promised a Senate debate this fall. The Democratic-led House has already passed background check legislation this year, but the N.R.A. has pressured Mr. Trump and other Republican leaders to back off new steps on background checks.
For the most part over the holiday long weekend, the Democratic candidates struck upbeat notes at events as they exchanged hearty handshakes and nice-to-meetchas, and dropped by picnics and ice cream socials in Iowa and New Hampshire.
The 2020 Democratic nomination remains very much up for grabs heading into Labor Day week, which traditionally marks the start of a fall campaign season when presidential primary fields winnow and more voters start picking favorites.
As the Democratic field stands now, 20 candidates are still running, but only 10 of them have qualified for the next two debates, on Sept. 12 and Oct. 15.
Of that group, just three candidates — Mr. Biden, Mr. Sanders and Ms. Warren — have consistently been in the double digits in recent polls. A fourth, Senator Kamala Harris, has dipped in some polls but has shown an ability to achieve breakout moments, as in her June debate performance, and remains a broadly appealing campaigner. Mr. Buttigieg and Senator Cory Booker are building out ground forces in Iowa, which votes first on Feb. 3, and Ms. Klobuchar is also making a push in that state.
At the same time, the field’s shape at summer’s end looks not unlike it did at spring’s end. Mr. Biden entered the presidential race in late April as the Democratic front-runner; he remains in that position, having withstood summer challenges from second- and third-tier contenders.
But Mr. Biden has yet to come under sustained attacks from his closest competitors at this point, Ms. Warren and Mr. Sanders, who have large numbers of deeply enthusiastic supporters.
Mr. Biden’s summer has hardly been a smooth ride. Mr. Booker and Ms. Harris attacked his record on race. Senator Kirsten Gillibrand did so on gender issues, before dropping out last week. Mr. Buttigieg, who is 37 years old, has built his campaign on an unsubtle age contrast with Mr. Biden, who is 76.
Yet more than four months after he opened his campaign, Mr. Biden remains the leader. Few of the Democratic county leaders and party activists who populate Iowa’s political class say they are thrilled with the former vice president, and many say there’s little enthusiasm for his candidacy, yet he remains atop almost all polls of Democrats, in Iowa and elsewhere.
In two weeks, the top three candidates will appear on a debate stage for the first time when the top 10 Democrats gather in Houston. ABC’s moderators are certain to draw contrasts between Mr. Biden and Ms. Warren, who have clashed on economic issues across the last three decades. Mr. Sanders, though ideologically more similar to Ms. Warren, shares with Mr. Biden a base of lower-educated and lower-information voters in the Democratic contest.
How Mr. Sanders, Mr. Biden and Ms. Warren will compete and contrast themselves with one another is one of the biggest questions of the autumn phase of the campaign — as is whether voters will rally around any particular candidate on issues like gun control.
Ann Haaser, 65, came to a house party for Ms. Warren in Hampton Falls on Monday wearing a red “Moms Demand Action” T-shirt. Ms. Haaser, a Democrat who is part of the Massachusetts chapter of the organization that advocates gun control, said that requiring a background check for every gun purchase is the most critical legislative step to take.
“If we put through policy that has been watered down so much that it’s not meaningful, that it’s not going to solve the problem, then that’s not what we want,” she said. “We have a big gun violence crisis in this country at this point.”
But other voters were more favorable toward bipartisan action.
Tom Slater, an 82-year-old Democrat at the house party, said the country needed to have universal background checks and a ban on assault weapons, and he spoke positively about creating a national licensing program for gun owners. But in the meantime, he suggested Democrats should support smaller changes.
“Whatever in a positive nature Republicans are willing to do, I think we ought to join it, but also state that this is not enough; we intend to do more,” he said as he waited in the rain in Ms. Warren’s selfie line.
Reid J. Epstein reported from Cedar Rapids, Maggie Astor from Peterborough, N.H., and Thomas Kaplan from Hampton Falls, N.H.