PORTLAND — Democratic presidential candidate Hillary Clinton told an adoring crowd Friday that the United States will return to what she called the failed Republican policies of trickle-down economics unless voters keep a Democrat in the White House in 2016.

“I want the American people to understand what the choice is,” said Clinton. “(Republicans) want to return to the failed policies of trickle-down economics. We can’t let the hard work that has been done by President (Barack) Obama to be ripped away.”

Clinton brought her campaign to the gymnasium of King Middle School, an aging building adjacent to Deering Oaks park. The setting was a stark departure from the scene that has surrounded previous presidential visitors, such as independent U.S. Sen. Bernie Sanders of Vermont, who attracted more than 7,000 people to Portland’s Cross Insurance Arena in early July. Organizers said more than 400 people attended Clinton’s event, squeezing into the gymnasium and an overflow room elsewhere in the school.

Clinton went to great lengths to associate herself with Obama. She started her speech by describing the nation’s struggling economy that greeted Obama when he took office in 2009.

“I don’t think President Obama gets the credit he deserves for keeping us from falling even further,” said Clinton. “The recovery is proceeding, but we haven’t finished what we need to do.”

Clinton cycled through a bevy of familiar Democratic principles, such as increasing funding for schools, creating partnerships between students and businesses, raising taxes and eliminating tax loopholes that benefit the rich, along with some ambitious energy goals that mirror rhetoric from Obama’s 2008 campaign.

“By the end of my first term, we will have installed half a billion more solar panels,” she said. “By the end of my second term, I want us to have enough clean energy to power every single home in America.”

Clinton also focused on a couple of issues that many don’t think find their ways into political campaigns enough: increasing treatment for mentally ill and drug addicted people.

“I did not think I’d be talking about substance abuse in my presidential campaign until I started campaigning,” she said. “Everywhere I go, people ask me, ‘what are you going to do about the heroin epidemic?’”

She also touched on what might arguably be the most important role for the next president: appointing U.S. Supreme Court justices.

“The next president may get three or four justices, who I hope will care more about a citizen’s right to vote than a millionaire’s right to buy an election,” Clinton said.

Clinton is the fourth presidential candidate who has visited Maine in recent weeks, though her visit last year in support of Democratic gubernatorial candidate Mike Michaud came well after she was presumed to be vying for the White House.

The Clinton campaign is doing well in Maine, according to early indicators such as endorsements. Among those lining up behind Clinton so far are House Speaker Mark Eves, former state Senator and 2nd Congressional District candidate Emily Cain, Senate Minority Leader Justin Alfond and U.S. Rep. Chellie Pingree, all Democrats.

But there also are signs that the race is changing. Clinton has taken heavy criticism in recent months over her use of private email accounts while she was secretary of state. In addition, her chief rival for the nomination, Sanders, is performing better than many people have predicted and Vice President Joe Biden is under pressure to join the race.

Maine Republican Party Executive Director Jason Savage said Clinton’s message was flat and that her talking points were “a mile wide and an inch deep.”

“Nothing will make the people of Maine trust her,” Savage said. “We heard a lot of platitudes instead of details and plans. She’s trying to rally a base in Maine that just isn’t rallying behind her.”

Alison Whitley traveled to the event from Sanford. She said she has never been to a rally like the one on Friday in Portland, but she couldn’t pass up the chance to meet someone who might eventually be president. She was able to have her photo taken with Clinton after the speech.

“I was impressed with how many issues she covered,” Whitley said. “She came across like a real person, especially when she was talking about her daughter and granddaughter.”

Bridget McFarland, a Bowdoin College student from California, said Clinton’s candidacy provides a rare opportunity to vote for a uniquely qualified woman with a shot at winning the presidency.

“That’s a really big deal for me,” she said. “It’s like, if it doesn’t happen now, when will it happen?”

Hillary Clinton waves to supporters during a campaign event on Friday, Sept. 18, at King Middle School in Portland.

Supporters fill up the gym before a Hillary Clinton campaign rally on Friday, Sept. 18, at King Middle School in Portland.