English: A County map of the 2020 Republican Presidential Primary.
Trump
Nevada, Arizona, Wyoming, North Dakota, South Dakota, Kansas, Virginia, South Carolina, New York, Alaska, Hawaii, Guam, Puerto Rico, American Samoa and the Northern Mariana Islands did not allocate Delegates by popular vote, instead choosing to pledge all Delegates to Donald Trump without holding a Primary Election. The U.S. Virgin Islands did hold a typical primary, but the official results were never reported. They are estimated to have been around 90% for Donald Trump. Nonetheless, Donald Trump won all 9 of the U.S. Virgin Island's Delegates. The U.S. Virgin Islands are colored black, as we lack any official information.
The states of Ohio, Georgia and New Jersey held elections, but Donald Trump was the only candidate. While other states also had Trump as the only candidate, there was still a write-in option. This was not the case for the aformentioned 3 states, so Donald Trump recieved 100% of the vote in every county in these states.
Source for county data:
https://www.nbcnews.com/politics/2020-primary-elections/nebraska-results/?icid=election_results#nbc-2020-05-12R--NE--P-dodge (Used for all states, not just Nebraska)