Check out the following newspapers & publications. Most of these papers are subscription only. They allow you to read a fixed number of articles per month. Some of these sources are available via databases. Those links are in the database column.
Check out the following recommended writers. You can also check them out on Twitter and Instagram.
Search for topic-based columnists by searching "syndicated columnists" and then the topic ("syndicated columnists LGBTQ" for example). Or search "best _______ editorialists" ("best environmental editorialists" for example). Just make sure that you are finding writers who specialize in opinions/editorials, and not investigative reporting.