Amassing a delegate lead after the Iowa caucuses and New Hampshire primary wasn't enough to propel Pete Buttigieg to victory in Nevada. Now, he's setting his sights on taking down front-runner and socialist Bernie Sanders.

With Sanders the Nevada caucuses winner, the former South Bend, Indiana, mayor is battling against former Vice President Joe Biden for a distant second place in Saturday's Silver State presidential nominating caucuses.

"Sen. Sanders believes in an inflexible, ideological revolution that leaves out most Democrats, not to mention most Americans," Buttigieg said Saturday night as caucus results were still trickling in. "Ours is the only campaign that has beat Sen. Sanders anywhere in the cycle," he added, a reference to winning more nominating delegates than Sanders in the Iowa caucuses.

Buttigieg is running ads in South Carolina, the next state to hold a primary on Feb. 29, taking aim at Sanders's Medicare for All single-payer healthcare plan that would eliminate private insurance.

Earlier on Sunday, Buttigieg's campaign compared Sanders with President Trump for his "toxic politics" and "fueling conspiracy theories" by questioning the timing of a Friday Washington Post report that Russia aims to aid Sanders's presidential campaign.

"We can prioritize either ideological purity or inclusive victory. We can either call people names online, or we can call them into our movement. We can either tighten a narrow and hardcore base or open the tent to a new and broad and big-hearted American coalition," Buttigieg said.

While Iowa and New Hampshire proved that Buttigieg is a serious presidential contender, Nevada is the first test of whether he can appeal to a demographically diverse electorate. According to the Census Bureau, just under half of the state's population is white, while 10% is black, 9% is of Asian descent, and 29% is Hispanic or Latino.

Buttigieg has long struggled to gain support among minority communities in polls and battled criticism of his handling of minority issues as mayor of South Bend. The Nevada result is a warning sign as he pushes forward to the South Carolina primary, where a majority of Democratic primary voters are black. A disappointing finish there could decisively stunt his momentum before Super Tuesday contests.

There were some signs that Buttigieg could come out ahead of Biden for second place in Nevada: He ticked up in Nevada polls after placing second in the Feb. 11 New Hampshire primary and tied with Massachusetts Sen. Elizabeth Warren at 14% in the RealClearPolitics average of national polls on Friday. Buttigieg targeted rural areas in Nevada, where individual votes disproportionately weigh more toward nominating delegates than in the populous cities of Las Vegas and Reno.

Before heading to South Carolina, Buttigieg is making a stop in affluent Arlington, Virginia, just outside Washington, D.C., on Sunday — an area where he enjoys lots of support from presidential campaign donors.