PHILADELPHIA, Pennsylvania — While Sen. Bernie Sanders (I-VT) declared Monday at the Democratic National Convention that “We have got to elect Hillary Clinton,” his supporters — who booed him — are having none of it.

They are out in force in the streets around the city, marching and demonstrating in the sweltering heat, which hit 91º F in the early afternoon but felt like 102º F with 56% humidity, according to AccuWeather.

Dozens gathered at City Hall, for example, while others marched down Broad Street, and others targeted the convention site itself.

Here are the thirteen best protest signs:

This sign was brought by activists from Connecticut, who were incensed at the news that thee Democratic National Committee had conspired to help Clinton defeat Sanders in the primary:

This sign went into greater detail, adding a new acronym for the DNC: “Dishonest, Nefarious, Corrupt”:

This gentleman summed it up with a simple equation:

Many protesters felt the entire primary election had been corrupt:

Likewise with this protester, who seemed to agree that votes had been stolen:

What is particularly endearing about this sign, which calls for Hillary Clinton to be “Berned” (i.e. “burned”), is the slogan on the protester’s T-shirt: “peace, love, Bernie for president 2016.”

Several protesters carrying signs threatening to leave the Democratic Party, and borrowing from the recent “#Brexit” from the EU, warned of “#Demexit”:

Call this the #NeverHillary faction:

One protester decided to play on the “Black Lives Matter” movement to describe Hillary Clinton’s corruption:

One sign referred to an actual quote by Hillary Clinton during the Democratic primary debates that “no individual should be too powerful to jail” (obviously, she didn’t mean herself):

There is an effort under way among Sanders supporters to reject the nomination of Sen. Tim Kaine (D-VA) as Hillary Clinton’s running mate, largely because of his support for the Trans-Pacific Partnership (TPP) free trade deal. That effort depends on delegates inside the convention hall — but has plenty of support beyond it.

Hillary’s hashtag is “#ImWithHer.” Trump says “I’m with you.” These protesters weren’t quite prepared to go that far — at least, not yet — but offered this version:

This sign calls the election “rigged” and advises its audience to “give up now” — though it’s not clear who should give up, or what they should concede.

And… one bonus poster, courtesy of President (then Senator) Barack Obama:

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. His new book, See No Evil: 19 Hard Truths the Left Can’t Handle, is available from Regnery through Amazon. Follow him on Twitter at @joelpollak.