Bernie Sanders suffered a devastating blow at the polls on Tuesday when he lost four of five states that voted, including Pennsylvania, one of the last states with a large enough delegate haul to tip the scales in his favor.

Hillary Clinton subsequently declared herself the presumptive Democratic nominee at an election night party in Philadelphia where she told fans she would ‘unify our party to win this election.’

Sanders’ supporters say she has a long way to go until that happens.

They feel Clinton has treated them 'disrespectfully' and want the senator to stay in the race until the bitter end.

Bernie Sanders suffered a devastating blow at the polls on Tuesday when he lost four of five states that voted, including Pennsylvania, but his voters remain loyal

They feel Hillary Clinton has treated them 'disrespectfully' and want the senator to stay in the race until the bitter end. Sanders supporters are seen here waiting for the senator last night in Huntington, West Virginia

More than a dozen states have yet to vote, but even Sanders seemed to admit last night at a rally in West Virginia and later in a statement that his time as a viable candidate is nearly up

‘Hillary would need to earn Bernie supporters' votes. She can’t just expect everybody to fall in line,’ Sanders supporter Samantha Avellino said Monday as she waited for the U.S. senator to arrive at a Philadelphia rally.

Avellino was one of 1,200 lucky Sanders backers who made it past security and into the Drexel University athletic center that night. As many more college-aged students were kept outside after the fire marshal pronounced the half-empty room at capacity.

Polling in the New England state foretold a race-changing win for Clinton, but Sanders’ young backers turned out in droves to see their political champion speak there and at a rally the next evening in West Virginia, where the crowd count was set at 6,400.

'Honestly, things aren't looking too great,' one attendee of the Philadelphia rally, Aaron Coleman, acknowledged.

But the fact that Sanders' events are turning so many people out, 'just having that,’ Coleman said, 'goes a long way to the future.'

Coleman’s friend Shanea Coburn agreed with him and said, ‘For the longest time, this age bracket, we weren't the big voters. And now I feel like we have someone who makes us actually feel like us as young people can make a difference.’

More than a dozen states and territories have yet to vote, but even Sanders seemed to admit last night at a rally in West Virginia and later in a statement that his time as a viable candidate is nearly up.

He promised to stay in the race through the last major primary on June 7 in California, though, and said that ‘people in every state in this country should have the right to determine who they want as president and what the agenda of the Democratic Party should be.’

The independent senator’s base agrees. Everyone who spoke to DailyMail.com this week said he should keep campaigning until Clinton is named the nominee.

Hillary Clinton subsequently declared herself the presumptive Democratic nominee at an election night party in Philadelphia where she told fans she would ‘unify our party to win this election.’ Sanders’ supporters say she has a long way to go until that happens

Philadelphia resident Joe Rockwell said, ‘He has a good message to spread, he's gaining more popularity....More people are going to start to get behind him or his message at least or become aware of it.’

‘I don’t think it detracts from anything, him staying in the race, ‘Ashland, Kentucky, resident Kathleen Murray said Tuesday night. ‘I think he represents a significant voice that Hillary needs to listen to and the rest of the Democrats need to listen to.’

Murray noted that surveys of Democratic voters indicate that a significant number of Sanders voters say they will not back Clinton in the general election.

‘She needs to listen, if she wants to unify the party,’ Murray stated. ‘She needs to listen to Bernie Sanders and his supporters.’

Clinton blew up on Monday night during an MSNBC forum at the suggestion that she needed to extend an olive branch to Democrats and independents who voted for Sanders in the state that have already held their contests if she wants them on her side in the general election.

‘I am winning!' she exploded. 'And I'm winning because of what I stand for and what I've done.'

Her opponent had said earlier in the evening, and in interviews the day before, that he was unable to ‘snap my fingers’ and make his voters see things her way – they’ll make their own decisions.

Now a Democrat, he’s said he’ll be a team player and do everything he can to keep Donald Trump or whoever the Republicans nominate out of office. Clinton will have to convince his voters she deserves their support, though, he’s said

Now a Democrat, Sanders has said he’ll be a team player and do everything he can to keep Donald Trump or whoever the Republicans nominate out of office.

Clinton will have to convince his voters she deserves their support, though, he’s argued.

At his Tuesday evening rally in Huntington, West Virginia, Murray said she agrees with him.

‘He's earned her respect whether he wins or not,' she said of his tenuous relationship with Clinton.

As to whether he should give her his endorsement and campaign for her, Murray said, ‘Well respect is given when it is earned.’

Sanders’ supporters are in agreement that Clinton would be better than the alternative – Trump or some other Republican.

For the most part, they remain unconvinced that Clinton cares about the issues that are important to them, though, and for some, that continues to be a sticking point.

‘Hillary's done a lot of shady things in the past that she's now bringing up and saying the opposite now,’ Sanders supporter Sweet Rodriquez said as she argued in Philadelphia with Coleman and Coburn about whether or not Clinton should have their support – and Sanders’ - in November.

The progressive senator's backers say they’d like to see Clinton move to the left on key issues like money in politics and release her Wall Street transcripts.

His backers say they’d like to see Clinton move to the left on key issues, like money in politics, and release her Wall Street transcripts

On the topic of campaign finance reform, Avellino said of Clinton, ‘She says that that’s a single issue, but that issue touches every other issue.’

At the same rally, Fred Kinglee said that Clinton ‘equating Bernie's ideas to some flight of fancy is disrespectful to his voting base.

‘How do you expect them to not only believe in you but think that you take some seriously,’ he asked, when you characterize their beliefs as a ‘form of ill reality, if based on reality at all.’

Kinglee bluntly added to the assertion, ‘Why would I want to support you?’

For him, a college graduate in his 30s, he said he's able to get past it.

‘But for the 22-year-olds in this room, you pretty much just told them everything they believe in is just BS.’

Avellino likewise said that she and her friends ‘feel a little bit mistreated’ by Hillary Clinton and her husband, former President Bill Clinton.

When they say things like ‘young people aren't aware of what's going on, they need to do their research,' it's off-putting, she said.