No. For example: https://www.washingtonpost.com/news/volokh-conspiracy/wp/2016/03/02/so-far-trump-wins-open-primaries-and-cruz-wins-closed-and-the-calendar-is-

No. For example: https://www.washingtonpost.com/news/volokh-conspiracy/wp/2016/03/02/so-far-trump-wins-open-primaries-and-cruz-wins-closed-and-the-calendar-is-starting-to-change-toward-more-closed-primaries/ https://www.washingtonpost.com/news/volokh-conspiracy/wp/201... (The url is the whole story).