Yes and no. Organic is certainly preferable, but there are caveats.
Fist of all, something could technically be called organic and be grown in poor mineral depleted soils and thus be nutritionally poor.
Second, and here is the big rub, to qualify as organic in most states a crop must be grown on soils that have had no chemical fertilizers, pesticides, herbicides or other chemicals applied within the past three years. Theoretically the soil could have been a toxic nightmare up until three years ago - and some pesticides and other chemical toxins have half-lives of 50 years or longer. Then there is the problem of aerial drift and water runoff from adjacent fields that are not organic. Thanks to a century of us trying to pollute and poision ourselves off the planet there really is virtually no toxin free soil left.
So, all in all organic is safer and more nutritious, but the only way to know for sure is to grow your own on soil you are familiar with.