CRESTON, Iowa—As a 25-year-old, Pete Buttigieg knocked on doors here in Union County as a volunteer for a Democratic presidential candidate with a relatively thin political resume and an uncommon name.
Twelve years after he played that small role in helping Barack Obama win the 2008 Iowa caucuses—a victory that launched the then-junior senator from Illinois on a path to the White House—Mr. Buttigieg is back, drawing parallels between himself and the former two-term president.
While Joe Biden, Mr. Obama’s vice president, frequently mentions his former boss during stump speeches as he argues that he wants to continue that legacy, it is Mr. Buttigieg among the top-tier candidates who is trying the hardest to mimic the former president’s campaign style.
His Iowa town-hall appearances now often start with the testimonial of a local organizer, just as Mr. Obama’s events frequently did 12 years ago. There are also Obama-like aspirational calls for hope.
“Going to caucus is an act of hope,” Mr. Buttigieg, the 37-year-old mayor of South Bend, Ind., said Monday at an event in Union County, one of three in Iowa where Mr. Buttigieg volunteered for Mr. Obama’s first presidential campaign, according to his autobiography.
“Volunteering, for sure, for a candidate that you believe in, is an act of hope,” Mr. Buttigieg said. “There is a kind of hope that propelled me and a couple buddies to rent a car out of Omaha and drive it to Creston and have a whole new life experience.”
The comparisons the mayor draws with Mr. Obama are designed to bolster the notion that his candidacy is also historic—he’d be the first openly gay man to occupy the White House—and that voters shouldn’t shy away from him just because he doesn’t have years of Washington experience.
Mr. Buttigieg holds leads in the most recent polls in Iowa and New Hampshire, the two states that hold the first nominating contests in early February. But his inability so far to attract support from black voters is hurting him in another early state, South Carolina, and it is one of his biggest challenges. While the eventual first black president trailed then- Sen. Hillary Clinton among black voters early in the race for 2008, African-American support surged after he won Iowa. Building that enthusiasm is likely to be more of a test for the mayor, who was criticized over his handling of a police shooting of a black man in South Bend earlier this year.