Angry Muslim American voters are tired of being ignored by the Democratic Party’s presidential candidates — even though they make up a fast-growing source of Democrat votes.

Only two of the party’s White House contenders, Bernie Sanders and Julian Castro, agreed to speak at Saturday’s presidential forum at the annual convention of the Islamic Society of North America (ISNA) which has drawn 30,000 attendees to Houston, Tex. this weekend.

But a dozen Dems, along with President Donald Trump, were invited, organizers said.

“If they’re serious about courting the Muslim vote, they have to show up,” advocate Wa’el Alzayat told Politico Friday. “The entire system is rigged to keep our issues out of the spotlight when it’s inconvenient.”

“We’ve recently realized the Muslim community has a strong voting bloc,” ISNA board member Lubabah Abdullah told the Guardian. “Unfortunately [anti-Muslim sentiment] has become the norm.”

“It’s important that the presidential candidates engage American Muslims directly on the issues that matter most to us,” said Kalia Abiade of the Pillars Fund. “We need the others to step up if they want our communities’ consideration.”

Muslim-American voters lean heavily Democratic, with about 66 percent of them identifying with the party, according to the Pew Research Center. All of the Muslim representatives currently serving in the US Congress are Democrats.

That leaves many of the ISNA attendees feeling snubbed by the candidates’ absence from their event.

“We often hear a lot of really nice words when people like Donald Trump go after Muslim Americans,” Abdul El-Sayed, gubernatorial candidate in Michigan last year, told Politico. “But there’s another side to this: You have to come and listen to the things we’re asking of our government if you want to leverage our pain.”

Federal prosecutors named ISNA as an unindicted co-conspirator in their case against the Holy Land Foundation, a group that was convicted of raising millions of dollars for Hamas, a State Department-designated terror organization.