Veteran anti-abortion activist  Randall Terry won more than 18,400 votes, or 18 percent, in Oklahoma's Democratic presidential primary Tuesday - a not insignificant showing in a year when incumbent President Barack Obama has nationally faced no serious challenge from within his party.

Obama won more than 54,000 votes, or 55 percent, according to preliminary results from the Oklahoma State Election Board. Democrats who turned out did so largely in a symbolic show of force for Obama in one of the nation's reddest states. (Republican Sen. John McCain carried Oklahoma with 65 percent of the vote in 2008 to Obama's 34 percent.)

Support for Terry highlights, at least in part, the prevalence of anti-abortion Democrats in the country's mid-section, where social issues are of comparatively higher salience for all voters.

Terry, who founded Operation Rescue, formally launched a primary challenge to Obama in January 2011 with the stated intention of raising the profile of his anti-abortion views.

"I want to pummel Obama. I despise this presidency. He is the arch child-killer of the Western Hemisphere, so I'm going to go head-to-head with him," Terry told ABC News in a phone interview at the time.