Can the ACLU be considered a fundamentalist organization?

Actually, the ACLU takes a broad reading of the constitution on most issues in that they include rights that are not only express from the text, but also implied from the text.

No, it is not a "fundamentalist" organization and they do not read the constitution literally. Rather, they look at its meaning, intent and values, which means they interpret it broadly, not narrowly, in order to preseve all of our civil rights. Simpletons who dislike the positions they take will always try to belittle them, but that doesn't matter since they are working to preserve the constitutional freedoms of the simpletons as well as the rest of us. Freedom and democracy need vigorous advocates, like the ACLU. otherwise the narrow-minded among us will do whatever they can to infringe upon our rights of freedom of speech, religion, press, and assembly because they dislike what others believe..

The ACLU does not do something to shelter 2d substitute rights or to motivate the preferrred courtroom to continuously uphold their doctrine of important due technique (inclusive of in financial concerns). luckily, the Institute for Justice and the gun rights lobbys are prepared to shelter the civil liberties that the ACLU does not shelter. If purely, we could get a libertarian president and a libertarian congress who might hire libertarian judges to the bench.

Depends on whether or Not You believe that pedophiles should be able to take advantage of children without Parental consent. They are fundamentally for that! Real Fundamentalists are strictly by the rules and Old school.

The Atheist Communist Litigation Union uses the Constitution with tounge in cheek. It takes and misuses what it wants and denies the rest even exists. Constructionalists they aren't. Left wing extremist whackos, they are.