Pete Buttigieg expected 50 people at a Des Moines town hall. Over 1,600 people showed up. The rally was his second of the day in Iowa.

The momentum of presidential candidate Pete Buttigieg's campaign forced a Tuesday night town hall outdoors in Des Moines, Iowa, to accommodate a much larger than expected crowd.

The campaign expected about 50 people for its town hall at the gymnasium at Benjamin Franklin Junior High school in Des Moines. The school estimated 1,650 people showed up.

Buttigeig spoke briefly and for the second time Tuesday answered questions from the crowd. During his brief remarks, he mentioned that Electoral College should be abolished, saying that whoever gets the most votes should be elected to office. Should that have been the case in 2016, Democrat Hillary Clinton outpaced Donald Trump in the popular vote.

Buttigieg, who is gay, spent a portion of the question and answer session addressing the issue, which has come into further focus after an interview on "Ellen" and trading jabs with former Indiana Gov. Mike Pence.

In Des Moines, someone in the crowd asked, "What do I tell my friends who say America isn’t ready for a gay president?"

“Good question. First, tell your friends, I say, 'Hi.' Tell them about Indiana in 2015," he said.

The mayor went on to describe life as a closeted man in Indiana in 2015, which "wasn’t an ideal place to be gay."

Buttigieg said he came out mainly because he realized he wanted to start dating and, "I realized when deployed [as a soldier in Afghanistan] my life could end and as a grown ass man I wouldn’t know love."

The candidate also returned to an ongoing back-and-forth with now-Vice President Pence, who was booed when mentioned. "You know my differences with the vice president," he deadpanned.

Buttigieg noted he came out during an election year and, "I got re elected with 80% of the vote."

For the second time in one day, Buttigieg was interrupted by a protester -- both in Des Moines and earlier in the day in Fort Dodge.

Buttigieg stayed at the microphone and at one point said, "We get it." The protester was escorted away, but he returned a few minutes later -- yelling again. Both times he was drowned out by cheers of "Pete Pete Pete!" by the crowd. Earlier, in Fort Dodge, he was interrupted by a protester who was screaming at the mayor that he’d betrayed his Baptist faith and, "We will not stop! This man is misleading our children."

After the man in Fort Dodge was escorted out, a person in the crowd yelled out, "Now we know what you go through Mayor Pete!”

Lis Smith, a communications adviser to the mayor who was asked by members of the press whether they have security at events, said that they have had to hire security.

Buttigieg was asked about a smattering of other topics as well.

Strategy for beating Trump

"He’s kind of like a Chinese finger trap: The harder you pull the more you get stuck. It's important to think about strategy," he said.

Buttigieg said Democrats are at risk because, “Every well-spoken Democrat … pictures being on the debate stage with that guy. We all have our things we’d like to say."

Buttigieg said that everyone thinks they have an idea that they’re “going to knock [Trump] flat with some zinger, it’s like we’re trying to impress him. We’re playing his game. That’s the finger trap. You can’t completely ignore it."

Gun violence

Buttigieg told the crowd that the National Rifle Association has struck fear in politicians because they mobilize people and that the anti-gun movement should, too.

However, the question was about gun violence research, so he said, "We should end the CDC research ban to look into this as a public health issue."

Funny moment about his book

A man named Scott submitted a question asking whether Buttigieg had changed his opinion from anything he wrote in his book.

"I guess I changed my mind about running for president," he said. "I had thought about it.

"Where’s Scott? Hey Scott! Thanks for reading the book! The book is how we’re paying off the wedding!" he said to laughs.

When finishing up his answer to the final question, Buttigieg told the crowd, “sounds like my time is up." The crowd groaned and someone yelled “Four more years!” The mayor laughed and said, “But I’ll be back,” and asked for the crowd’s support.

Buttigieg and his husband spent about 45 minutes shaking hands and talking to members of the crowd after the Q and A.

ABC News' Mark Osborne contributed to this report.