Fighting for the natural order and human life in the image and likeness of God is an obligation in charity for your neighbor, but not based on the terms of another's religion and false paradigm of the family the neo-sspx accepts: abortion wrong, contraception accepted, ecumenism is a right. This is what the neo-sspx is saying Marching with, and under, the novus ordo pilgrimage against abortion. One cannot exclude oneself standing under the ecumenical banner of conciliarism in the eyes of the world and say you do not support their aims.
Archbishop Lefebvre, to quote only a few of his words, has said with respect to Vatican II:
“The more one analyzes the documents of Vatican II, and the more one analyzes their interpretation by the authorities of the Church, the more one realizes that what is at stake is not merely superficial errors, a few mistakes, ecumenism, religious liberty, collegiality, a certain Liberalism, but rather a wholesale perversion of the mind, a whole new philosophy based on modern philosophy, on subjectivism… A wholly different version of Revelation, of Faith, of philosophy! Very grave! A total perversion! How we are going to get out of all this, I have no idea, but in any case it is a fact, and as this German theologian shows (who has, I believe, another two parts of his book to write on the Holy Father's thought), it is truly frightening. So, they are no small errors. We are not dealing in trifles. We are into a line of philosophical thinking that goes back to Kant, Descartes, the whole line of modern philosophers who paved the way for the Revolution.” (Two Years After the Consecrations, September 6, 1990)
“We believe we can affirm, purely by internal and external criticism of Vatican II, i.e. by analyzing the texts and studying the Council’s ins and outs, that by turning its back on Tradition and breaking with the Church of the past, it is a schismatic council.” (Archbishop Lefebvre, Le Figaro, August 4, 1976)
“It is stupefying to read in the Documentation Catholique that the Lutheran-Catholic Commission of the Secretariat for Christian Unity, and thus an official Roman commission, said in effect that numerous points in the Council were drawn from the teachings of Luther…” (Conference in Germany, October 29, 1984)
“This Council gives the same rights to error as to Truth! That is impossible.” (Conference, May 11, 1976)
“This reform, since it has issued from Liberalism and from Modernism, is entirely corrupt. It comes from heresy and results in heresy, even if all its acts are not formally heretical. It is thus impossible for any faithful Catholic who is aware of these things to adopt this reform, or to submit to it in any way at all. To ensure our salvation, the only attitude of fidelity to the Church and to Catholic doctrine, is a categorical refusal to accept the reform.” (Declaration of Faith, November 21, 1974)
-“The Church, in the course of the 1960's, thus during the Council, acquired values that have come from outside the Church, from the liberal culture - due secoli - from two centuries of liberal culture. It is clear: these are the "rights" of man, it is religious freedom, it is ecumenism. It is Satanic.” (Conference, December 13, 1984)
But now since 2012, the SSPX tells us its ok to join forces and 'march together' with those who so gravely offend Almighty God.
They have abandoned the true Church, the son of Promise (Isaac) and placed themselves under the son of nature (Ismael).
St. Paul tells us in Galatians, Chapter 4, 22-23; 28-31:
For it is written that Abraham had two sons: the one by a bondwoman, and the other by a free woman.  But he who was of the bondwoman, was born according to the flesh: but he of the free woman, was by promise. ...
Now we, brethren, as Isaac was, are the children of promise. But as then he, that was born according to the flesh, persecuted him that was after the spirit; so also it is now. But what saith the scripture? Cast out the bondwoman and her son; for the son of the bondwoman shall not be heir with the son of the free woman.
So then, brethren, we are not the children of the bondwoman, but of the free: by the freedom wherewith Christ has made us free.
Let us not throw off the true Church for the false one. We cannot 'march together' with those who do love the true Church, the only one founded by Our Lord Jesus Christ. The Conciliar Church (as they call themselves) is not the true Church. It is an aberrancy.
We pray for them but do not submit or join them. That is a betrayal of the true Faith.
"So let us be confident, let us not be unprepared, let us not be outflanked, let us be wise, vigilant, fighting against those who are trying to tear the faith out of our souls and morality out of our hearts, so that we may remain Catholics, remain united to the Blessed Virgin Mary, remain united to the Roman Catholic Church, remain faithful children of the Church."- Archbp. Lefebvre 1980