A counterterrorism expert said Abdul El-Sayed's Senate bid raises security concerns due to family ties to Muslim Brotherhood groups and connections to a voter-engagement organization tied to CAIR.

During a Senate hearing on Muslim Brotherhood threats, Sen. Ted Cruz asked Kyle Shideler about El-Sayed's bid. Shideler explained that El-Sayed's father-in-law has connections to Muslim Brotherhood groups. The hearing was boycotted by Democrats. Sen. Cruz led the discussion.

Shideler told Cruz that El-Sayed's bid raises concerns because of his father-in-law's alleged ties to Muslim Brotherhood groups.

Shideler mentioned that El-Sayed's father-in-law was the president of CAIR-Michigan and was on the Islamic Society of North America Founders Committee. This committee is for those who are very devoted to ISNA and give a lot of money.

Democrats were criticized for skipping a crucial hearing on radical groups in the US.

Abdul El-Sayed is a progressive candidate in the Democratic primary for US Senate in Michigan. He spoke at a primary election night event in Detroit.

Shideler testified that there are other known Muslim Brotherhood members on the committee. He also looked at El-Sayed's ties to Emgage, a group that helps Muslims get involved in voting and politics, but has close ties to CAIR.

Emgage's founder, Khurrum Wahid, said the group helps Muslim Americans participate in public service.

Shideler said Emgage was created by a former CAIR member who was on a terror watchlist and was a consultant to convicted terrorist Sami al-Arian.

There are concerns about El-Sayed's ties to extremist groups and antisemitism among Jewish voters.

In 2012, a Times of Israel article criticized Rep. Debbie Wasserman-Schultz for speaking at a fundraiser hosted by Wahid, who was on the federal terror watch list.

In 2006, Al-Arian pleaded guilty to conspiring to provide services to the Palestinian Islamic Jihad.

Fox News reached out to Wahid's law firm and El-Sayed's campaign for comment.

During the hearing, Cruz also asked Shideler about the 'Red-Green Alliance' and its ties to the Democratic Socialists of America.

Liz Peek wrote that Michigan can stop the socialist movement or watch it take over the Senate.

Cruz asked if the Muslim Brotherhood partners with groups like the Democratic Socialists of America.

Shideler testified that they do.

Cruz said the Red-Green Alliance shares hatred of Western civilization, democracy, and capitalism. Shideler agreed and said they also want to overthrow the US Constitution.

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Shideler said the Muslim Brotherhood has active chapters in the US.

El-Sayed has been criticized for ties to radical voices and declined to comment on the killing of Iranian Supreme Leader Ayatollah Ali Khamenei.

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A Fox News review found that El-Sayed accepted donations from at least 41 individuals tied to CAIR.

Fox News' Andrew Mark Miller and Kiera McDonald contributed to this report.

The author of this report was born and raised in Allentown, Pennsylvania, and has worked for Fox News since 2013.