WASHINGTON, Iowa — They share awkward glances at events where nearly everyone looks like them. They take comfort in reminding one another that they propelled Barack Obama to the White House. They swear that their values and priorities are representative of more than a Corn Belt farm state.

With less than two months until the Iowa caucuses begin the presidential nominating process, the sense of duty among white Iowans has never been greater — or more complex. Already confronting questions about whether their overwhelmingly white state should retain its pre-eminent position in the primary process, many Iowa Democrats are consumed by a desire to select a coalition-building Democrat who can beat President Trump. So they are fixated more than ever on backing a candidate they believe can win in more diverse states than their own.

“I think ‘responsible’ is a good word,” said Lisa Yoder, 56, a retired teacher from Kalona, who came to an event in Washington recently to see Pete Buttigieg speak. “We want someone who the nation will get behind and support — everyone, not just the white Iowans.”

It is a preoccupation that is bedeviling liberal white voters across the country. It has also paralyzed voters, racking them with indecision as they try to identify a candidate who can prevail across a range of voting blocs, including minority communities as well as suburban and working-class voters.