Analyst Daryl Johnson on Wednesday said the U.S. government was mistaken to focus its counter-terrorism efforts almost exclusively on al-Qaida.

"The threat from domestic terrorism motivated by extremist ideologies is often dismissed and overlooked in the national media and within the U.S. government," he said at a Senate Judiciary hearing. "Yet we are currently seeing an upsurge in domestic non-Islamic extremist activity, specifically from violent rightwing extremists. While leftwing attacks were more prevalent in the 1970s, today the bulk of violent domestic activity emanates from the rightwing."

Johnson noted that Muslims extremists had carried out five attacks in the United States since the 9/11 terror attacks, resulting in the deaths of 17 people.

In contrast, since 2008, rightwing extremists killed 16 police officers and wounded 27 others, he said. Since 2009, one abortion doctor was murdered and six clinics that provided abortion services were bombed -- all presumably by rightwing extremists. Most recently, Johnson noted that a white supremacist killed six worshipers at a Sikh temple in Wisconsin. Numerous anti-government plots have also been foiled by law enforcement.

Johnson said Muslim extremism posed a real threat, but insisted it was wrong for the U.S. to only be concerned about Islamic radicals. Both leftwing and rightwing extremists -- particularly those who formed small, independent groups -- also posed a terrorist threat.

"Violent extremism is a growing threat in the United States," Johnson said. "The threat emanates from extremist belief systems that represent a broad range of religious, political and social causes."

Johnson formerly worked at the Department of Homeland Security (DHS), where he authored a report about rightwing extremism. Conservative pundits blasted the reporting, alleging that the Obama administration was trying to criminalize rightwing views. Under pressure, the DHS repudiated the report.

Watch video, courtesy of CSPAN, below: