By Elise Viebeck - 11/27/12 10:16 PM EST
"He should figure out why he decided to take that position [to oppose abortion rights] in the first place," said SBA List President Marjorie Dannenfelser.
"The folks that have taken the stand on this issue have taken it because we're talking about defending vulnerable human life. If it's not about that, it's not about anything."
The group also released a quote from Martin Luther King Jr. meant as a "direct challenge" to McCain: "In the end, we will remember not the words of our enemies, but the silence of our friends."
Personhood USA took a more direct tact in an earlier statement, calling on the GOP to "drop" its former presidential candidate over his desire for a de facto truce on abortion.
"We will never be successful if we compromise," said Jennifer Mason, the group's communications director.
"Politicians such as Senator John McCain seem to believe that compromising and backing down on difficult issues is the answer, but we will only find success when we stand up and fight for what we believe in."
Debates are brewing on the right about how the Republican Party should move forward on issues like abortion given the GOP's poor showing on Nov. 6.
Republican losses in at least two Senate races were blamed on comments related to abortion that alienated centrist women voters.
McCain is the most high-profile GOP lawmaker to call for a more conciliatory tone on abortion in light of the elections.