West Lafayette, Indiana(CNN) Facing daunting delegate math, Bernie Sanders now has a back-up plan: to force Democrats to adopt "the strongest progressive agenda that any political party has ever seen."
In his first campaign event after Hillary Clinton crushed Sanders in four East Coast primaries, the Vermont senator told a crowd of college students Wednesday at Indiana's Purdue University that he won't exit the Democratic race despite Clinton's massive advantage in the delegate race.
"Let me make this clear, so that there's no confusion: We are in this campaign to win and become the Democratic nominee," Sanders said to cheers.
But he also acknowledged the reality that Clinton has a lead of more than 300 pledged delegates, and once super delegates are included, CNN estimates she has 2,168 of the 2,383 she needs to win the Democratic nomination.
"We are in this campaign to win, but if we do not win, we intend to win every delegate that we can, so that when we go to Philadelphia in July, we're going to have the votes to put together the strongest progressive agenda that any political party has ever seen," Sanders said.
He continued, "And our job, whether we win or whether we do not win, is to transform not only our country, but the Democratic Party -- to open the doors of the Democratic Party to working people and young people and senior citizens in a way that does not exist today."
Sanders made the case that he's the more electable general election candidate because he can draw more independents into the process than Clinton.
"I am very good in arithmetic, and I can count delegates, and we are behind today," he said. "But you know what? Unusual things happen in politics, and with your help, we are going to win the pledged delegates, and with your help, super delegates may well reach the conclusion that Bernie Sanders will be the strongest candidate against Donald Trump."
Sanders pledge to win was a different message than his statement that was distributed after Tuesday's results, which some translated as repositioning the campaign off winning the nomination to focusing on altering the party's platform.
"That is why this campaign is going to the Democratic National Convention in Philadelphia with as many delegates as possible to fight for a progressive party platform that calls for a $15-an-hour minimum wage, an end to our disastrous trade policies, a Medicare-for-all health care system, breaking up Wall Street financial institutions, ending fracking in our country, making public colleges and universities tuition free and passing a carbon tax so we can effectively address the planetary crisis of climate change," Sanders said in the statement.
Sanders' campaign manager said the statement was "absolutely not" a concession of the nomination fight, adding, "This has been a campaign for the nomination, it continues to be."
Sanders did not back down at Wednesday's event on his criticisms of Clinton, despite Clinton offering an olive branch to Sanders and his supporters in her victory speech on Tuesday night.
Instead, Sanders stuck to comparing and contrasting their records, hitting her for a $12-an-hour minimum wage that falls short of his call for a national minimum $15 wage. He also hit her on trade, fracking, and a tax on carbon. And he did not let the opportunity pass to hit her for the speeches she made to Wall Street -- though he didn't make his common demand to "release the transcripts."
The senator also criticized the Clintons, both of them, in a bigger picture argument he made about taking on the establishment.
"We were taking on the most powerful politician organization that had elected Bill Clinton for two administrations and run a very strong campaign in 2008," he said of the odds being stacked against his bid since day one.
At Sanders' rally at Purdue, supporters who'd just heard him lay out the delegate math were coming to grips with the reality that the nomination now looks out of their candidate's reach.
"It would be close to a miracle for it to happen, but you do have massive states like California," said David Mason, a 42-year-old Lafayette photographer.
"I'm not going to hold my breath," he said, "but I'll be canvassing this Saturday with my daughter here in Lafayette."
Republican front-runner Donald Trump made a play in a Tuesday night speech for Sanders supporters -- but none at Wednesday's rally were interested in backing the real estate mogul.
Some, though, said they'd back the Green Party's Jill Stein.
Jeremiah Beaver, a 36-year-old video editor from Indianapolis, said he's "ashamed" that he skipped 2012's election because he felt like Obama had "sold us out." This time, though, he'd back Stein, he said.
"I've been thinking about this a lot: What is Clinton going to do when the 40% of progressives and independents walk away?" Beaver said. "Because we will."
Other Sanders supporters, though, said they're too afraid of Trump to back the Republican. Eighteen-year-old Noblesville high schooler John Parke said he'd support Clinton if she defeats Sanders.
"The debate Bernie and Hillary are having is the right kind of debate: Whether there should be debt-free college or free college," he said, "not whether we should just do nothing."