AUGUSTA, Maine — Maine’s Democrats rallied around their U.S. Senate candidates and President Barack Obama’s re-election bid and against former Gov. Angus King and Republicans in Augusta and Washington, D.C., on Saturday, the second day of the party’s three-day convention at the Augusta Civic Center.

The Democrats’ convention, which about 1,500 delegates were expected to attend, focused largely on the party’s attempts to rebuild and elect majorities in the Maine House and Senate.

“We learned from our mistakes in the 2010 election and we pledge that never will it happen again,” said Barry Hobbins, the convention chairman and Democratic leader in the state Senate, referring to the Democrats’ loss of the governor’s office and both legislative chambers.

The Democrats’ gathering stood in stark contrast to the Maine Republicans’ convention last month, where supporters of Ron Paul took over convention proceedings, prevented the party’s Senate candidates from addressing the full convention and elected a slate of Paul supporters as delegates to the GOP’s national convention in Tampa, Fla.

Democrats gathered in Augusta ostensibly to settle on a platform, choose delegates to the party’s national convention in September in Charlotte, N.C., select Democratic electors to the electoral college and elect Maine representatives to the Democratic National Committee. But the first two days of the three-day confab served mostly as a chance to drum up publicity and enthusiasm for the party’s candidates.

The convention was the biggest venue yet for the four Democrats hoping to take Olympia Snowe’s seat in the U.S. Senate. The candidates, who square off against each other in the June 12 primary, took digs at King, criticizing him for refusing to p ublicly commit to caucusing with one party or the other once in the Senate.

“This self-anointed King expects he will take Maine’s seat in the U.S. Senate and that we will stand down,” said state Sen. Cynthia Dill of Cape Elizabeth, a civil rights lawyer. “In this historic election, if we concede this seat out of fear, fear will forever guide us and we will no longer be the party of hope.”

Dill and Rep. Jon Hinck of Portland called for a repeal of George W. Bush-era tax cuts, a single-payer health care system and investing tax revenues in education rather than in military efforts in Afghanistan and Iraq.

Policies such as the Bush-era tax cuts and the Iraq war are largely responsible for running up the United States’ national debt, Hinck said.

“Let’s not let the party who championed those policies tell us that they’re going to fix it,” he said. “I don’t even want to hear somebody who might caucus with what party tell us how to fix it.”

Benjamin Pollard, a Blue Hill native who founded a Portland ecological construction firm, gave a modest, self-deprecating speech focused largely on U.S. foreign policy, human rights and fair trade. He called for putting people to work on a nationwide rail system as an investment in public infrastructure and in an expanded Peace Corps and domestic civil service corps.

Pollard said he’s not the typical political candidate. “I don’t like fundraising. I don’t like promoting myself,” he said. “I’m not only an idealist, I’m an optimist.”

Former Secretary of State Matt Dunlap called on Democrats to stand up for their values and ordinary people.

“My big picture is that neighbor of mine who goes to McDonald’s every day in February not to have lunch but to get warm,” he said. “The entrepreneur who gives up his business and the dreams that go with it because they need a job with health insurance.”

Democrats also heard from legislative leaders in the Maine House and Senate, who trotted out a new party slogan, “We have your back,” and promised to take the majority in both chambers in November.

“We are not the minority,” said House Minority Leader Emily Cain, of Orono. “We are the re-emerging majority.”

The keynote speaker, Gov. Martin O’Malley of Maryland, took digs at Maine Gov. Paul LePage during an address urging Obama’s re-election.

“When we hear people like Gov. LePage and Mitt Romney say they want to take America back, we ask, back to what?” said O’Malley, chairman of the Democratic Governors Association. “Back to the 1950s? Back to the days of George W. Bush and all those job losses?”

LePage’s political team released a document before O’Malley’s address calling him “one of the most prolific tax-hiking governors in America.”

“Some of these tea party, new-age Republican governors like LePage worship the false idol of tax cuts,” O’Malley told reporters. “Creating jobs is more complex than simply eliminating the tax responsibilities of your highest earners.”