By that argument, no abolitionist except for John Brown actually believed that chattel slavery was wrong. No suffragettes except the anarchists actually believed that women should have the right to vote. No blacks in the USA in the 1960s actually believed they were equal in dignity with their white brothers.
Non-violent responses to violent outrages are a very Christian approach to the problems of evil. That doesn't mean there's no suffering involved. Pro-life activists are regularly arrested, assaulted, battered, and insulted. Pro-life organizations spend millions of dollars (gifted in charity by hundreds of thousands of pro-life people) every year helping woman who find themselves in difficult positions choose life and give their children a better life after birth. Time and treasure poured out for a cause are a better measure of the importance of a cause that the total weight of bullets expended in overcoming the other side.
The side that triggered the Civil War was the side that was in the wrong, so I'm not sure what truth you are pointing to there.
However, their rhetoric goes much further than that. Their rhetoric says that abortion is equivalent to murder, and thus justifies curtailing inalienable rights held by women.
The right of self-defense of others is something very close to universally accepted. If there were an equivalent number of five year old kids being aborted, we would not see milquetoast efforts like sit-ins and prayer vigils, actions with both little consequence and impact.
I believe Eric Rudolph believed abortion is murder. But all those people at prayer vigils, sit-ins, Red Rose Rescue, and pregnancy centers do not. They see it as something bad, but less than murder.
If a half million five year old kids are being murdered, you can't just go about your life and attend an annual March for Life protest. What kind of a person doesn't do more? This is systematic, legal, mass-scale child murder we're talking about.
Precisely this -> It is a common technique that someone believes in Position A because of reason X, but reason X is unacceptable to the wider society and won't win debates. You make up reason Y to rationalise your Position A.
Peole will debate you on reason Y and be wondering why they can't convince you despite demonstrating that reason Y is wrong. They can;t convince you because you don't care about Reason Y, it's just a ruse. Often your followers also know that reason Y is a ruse, at least the ones who are not totally stupid.
In the Brexit debate, you would have people claiming that it's about national sovereignty and 'all them bloody EU laws', but they wouldn't be able to name a single EU law. They never knew and cared about EU law, they had a problem with immigration.
If at least the country was discussing immigration, maybe they could discuss if it's cheaper to give some extra money to people who are affected by immigration or suffer the collateral damage of Brexit.
If this belief of theirs isn't real, none of them are. Which I think is actually true. They believe in nothing.
That's where you are wrong. What action exactly are you looking for that would make you respect their beliefs? Apparently its outside the law.
What they do believe, however, is that any woman who may need an abortion was being promiscuous, and should be punished for her actions. They absolutely believe that.
Any argument otherwise could equally justify any genocide.
If there were 500,000 five-year-old kids being murdered every year, with the explicit approval of the government, there would be a civil war.
The fact that the overwhelming majority do not do anything is proof positive that they do not believe abortion is equivalent to murder.
You can't simply claim, oh, I believe in democracy, or I believe in the rule of law in the face of a government that actively murders hundreds of thousands of children. No one has such a deep attachment to the rule of law for its sake as to tolerate 500,000 explicitly-legal child murders.