Josh Lintereur, and Jason Smathers

Sheboygan Press

Democratic hopeful Bernie Sanders came out swinging at former Secretary of State Hillary Clinton and Gov. Scott Walker in a wide-ranging speech in Sheboygan Friday afternoon, where he urged his supporters to push a "political revolution" beyond the presidential campaign.

The independent Vermont Senator, who spoke for about an hour to a crowd of 2,000 at Sheboygan South High School, drew a clear dividing line between himself and Clinton, who currently leads the delegate count in the Democratic contest.

Sanders referenced a video posted Thursday in which Clinton argued she was "sick" of his campaign for "lying" about her ties to the fossil fuel industry, saying she hasn't taken money from the industry during her campaign. Sanders countered that records cited by Greenpeace showed she'd received $4.5 million in contributions — either through her campaign or her SuperPAC — from lobbyists for the fossil-fuel industry.

"These are not just workers, these are paid, registered lobbyists," Sanders said. "Secretary Clinton, you owe our campaign an apology. We were telling the truth.”

A statement from Clinton's communications director released after the speech made it clear that she would do no such thing.

"It's disappointing that they've doubled down on negative character attacks that deliberately mislead voters rather than debate the issues," the statement read. "Their latest attack over campaign contributions ignores their own donations from individuals who work for oil and gas companies, and most importantly it ignores Hillary Clinton's record and agenda."

Related: Guide to candidate events in Wisconsin

Sanders continued to hammer Clinton's record on foreign policy, pointing to her vote to authorize the war in Iraq as one of the largest blunders in American foreign policy. In contrast to some other points Sanders made throughout his speech, this comment received only scattered applause.

Sanders also took specific aim at Wisconsin Gov. Scott Walker for what he said was not properly funding education, pushing anti-union legislation and promoting Voter ID requirements in the state. The April primary vote will be one of the biggest tests of Voter ID on a statewide level since it was fully implemented.

“I say to Scott Walker and other governors around the country: if you are afraid of free and fair of open elections, get out of politics,” Sanders said.

"I will be very much the opposite as president of the United States of America as Walker is as governor," he added.

Sanders arrived to cheers of supporters and one person who shouted out that they loved the Vermont Senator, to which he responded: "You know what, I love you too.”

“It is time to not only elect a new president but to transform our country,” Sanders said after taking the stage.

Sanders spent a good deal of his speech emphasizing the need to eliminate income inequality in the United States, saying ordinary Americans are being undermined by a "rigged economy" that abandons the middle class. He has advocated a $15 minimum wage as part of that plan.

"Are you ready for a radical idea?" Sanders asked the crowd. "Together, we are going to create an economy that works for all of us, not just the top 1 percent."

He also spent time blasting the Supreme Court's Citizens United decision that struck down campaign spending limits on corporations, saying it's opened the door to "billionaires buying elections."

Later, he outlined his plan to offer free college tuition at public universities, saying a college degree is now the same as a high school diploma 50 years ago and that young people should be rewarded for attending college, not "punished."

He proposed funding that plan by implementing a tax on financial transactions that he said would target "Wall Street speculation."

"We bailed out Wall Street, now it's Wall Street's time to help out the middle class," Sanders said.

But the one line that got some of the loudest applause of the afternoon was an attack on Republicans regarding their stance on gay marriage.

"When they talk about family values they are talking about making it impossible for our gay brothers and sisters to get married. I disagree,” Sanders said.

Sanders closed the event by saying that income inequality, health care, tuition and other issues that he's made central to his campaign are the defining challenges of our time.

"I believe that today we are in a pivotal moment in American history," he said. "These are the issues that people are now thinking about, and what people are saying is, 'enough is enough.'"

Supporters began lining up as early as 8 a.m. for a chance to hear Sanders speak.

Two sets of bleachers set up on either side of the fieldhouse were full, along with the floor seats.

Seating was capped at about 2,000 people — the facility can hold about 3,400 — campaign officials said.

A long line of supporters wrapped around the west end of the building just after noon, as organizers went up and down the line urging supporters to help canvass the Sheboygan area ahead of Tuesday's presidential primary vote. One spoke specifically about trying to "run up the delegate count" as much as possible by increasing Sanders' possible victory margin.

During his speech, Sanders on multiple occasions said that if voter turnout is big, he expects to win Wisconsin.

JoAnn Masche-Daane, of Beaver Dam, was second in line after arriving at about 8 a.m. She saw Sanders speak in Madison earlier this week but didn't have a good seat and was determined to not let that happen again.

Masche-Daane said she'd been apathetic about politics before Sanders got her attention with his honesty about the issues facing this country.

"He really woke me up...when he started talking about stuff and about what's really going on in this country," she said.

Hazel Dulmes, a Sheboygan native and freshman at UW-Madison, said she's supporting Sanders over Clinton, as she views him as more trustworthy. She also favors his proposals to provide free public college tuition and to legalize marijuana.

"I think he's been consistent throughout his political career," she said.

Also consistent has been the young demographic turning out at Sanders' rallies, and Sheboygan has been no different, with students not old enough to vote showing up to show their support.

"He's really passionate about his ideas. and I think we just really need a passionate candidate who really wants to change things for the betterment of everyone," said Helen Flynn, who's a freshman at South High.

The independent Vermont Senator is the first presidential candidate on either side to visit Sheboygan in advance of Wisconsin’s April 5 primary and is looking for supporters to help deliver a big win, with 86 delegates at stake.

The Sheboygan visit comes as Sanders contends that he’s now seized momentum in the primary race with Democratic rival Hillary Clinton.

Clinton enters April with a big delegate lead and insider support among Democrats crucial to the nomination.

But Sanders is pointing to victories in five of the past six states holding contests — among them, three western states — and views Wisconsin as a home for the progressive causes he has long supported.

Sanders still faces significant hurdles. Clinton has won 1,243 pledged delegates compared to Sanders' 980, according to a count by The Associated Press.

Clinton's lead grows when including superdelegates, or party officials like members of Congress and state leaders who can back any candidate they wish. Including superdelegates, Clinton has 1,712 delegates to Sanders' 1,011. It takes 2,383 to win and Clinton's team has suggested April 26 primaries in Pennsylvania, Maryland, Connecticut, Rhode Island and Delaware as a time when it could essentially seal the nomination.

Sheboygan Press reporter Phillip Bock contributed to this story, along with the Associated Press. Reach USA TODAY NETWORK-Wisconsin Reporter Josh Lintereur at 920-453-5147, jlintereur@gannett.com or on Twitter @joshlintereur