This public opinion survey indicates that there are key differences between moderate and liberal democrats.
Introduction
Yes, especially on how to handle Iran, illegal immigrants, and whether the United States is the greatest country in the world.
While Democratic presidential candidates are united in their opposition to the Trump administration’s actions, they have tried to distinguish themselves along progressive and more moderate lines on key issues. Overall, Democrats among the American public—including those who consider themselves “liberal” Democrats and “moderate” or “conservative” Democrats—share a similar foreign policy outlook based on US international participation, alliances, and international trade. But there are key differences that might influence which candidates voters choose. Differences include the degree to which Americans consider climate change, the Iranian nuclear program, and US political polarization a threat to US national security. Moreover, liberals and moderate/conservative Democrats differ in their perceptions of the most effective ways to address illegal immigration, the nuclear threat from Iran, and whether the United States is the greatest country. 
Key Findings
- Moderate/conservative Democrats are more alarmed than liberal Democrats by the nuclear threats from Iran (68% vs. 39%) and North Korea (69% vs. 57%).
- Majorities of both groups say that climate change is a critical threat, but a greater percentage of liberal Democrats are concerned (90% vs. 63%).
- A majority of liberal Democrats (59%), but only a minority of moderate/conservative Democrats (41%), believe that US political polarization is a critical threat.
- Liberal Democrats more heartily endorse diplomatic initiatives like humanitarian and economic aid and participating in international organizations as making the United States safer. 
- Moderate/conservative Democrats are somewhat more likely than liberals to say that maintaining US military superiority makes the United States safer.
- Nearly half of moderate/conservative Democrats support the use of airstrikes (48%), cyberattacks (49%), and US troops against Iran (45%) if Tehran restarts nuclear weapons development. Majorities of liberal Democrats oppose these measures (65% for airstrikes, 47% for cyberattacks, 65% for sending troops).
- Both groups support immigration, but moderate/conservatives are more likely to favor imposing new fines on businesses that hire illegal immigrants (61% vs. 49% liberal), increasing border security (66% vs. 47% liberal), and carrying out more arrests and deportations (42% vs. 19% liberal). 
- While a majority of moderate/conservative Democrats believe that the United States is the greatest country in the world (57%), only 39 percent among the liberal group agrees (with 59% saying it is no greater than other countries). 
- Majorities of both Democratic groupings say that the distribution of income and wealth in the country has become less fair, but the difference between them has grown since 2008 (currently 84% liberal Democrats, 64% moderate/conservative Democrats).
Methodology
The analysis in this report is based on data from the 2019 Chicago Council Survey of the American public on foreign policy, a project of the Lester Crown Center on US Foreign Policy. The 2019 Chicago Council Survey was conducted on June 7-20, 2019 by IPSOS using their large-scale nationwide online research panel, KnowledgePanel, among a weighted national sample of 2,059 adults, 18 years of age or older, living in all 50 US states and the District of Columbia. The margin of sampling error for the full sample is ±2.3, including a design effect of 1.1607. The margin of error is higher for partisan subgroups or for partial-sample items.
Partisan identification is based on respondents’ answers to a standard partisan self-identification question: “Generally speaking, do you think of yourself as a Republican, a Democrat, an Independent, or what?”
Ideological identification is based on respondents’ answer to an ideological self-identification question: In general, do you think of yourself as: [Extremely liberal, liberal, slightly liberal, moderate, slightly conservative, conservative, extremely conservative]
The 57 percent of Democrats who identify as very liberal, liberal, or slightly liberal constitute 21% of the overall sample. The 43 percent of Democrats who identify as Moderate/conservative constitute 16% of the sample (Moderates = 12.5%, Conservatives = 3.5%).
