The current president has previously spoken of it multiple times [0, 1] and has already authorized domestic military deployments, albeit not against citizens [2].

[0] https://www.cnn.com/2024/10/13/politics/trump-military-enemy...

[1] https://www.washingtonpost.com/elections/2024/10/24/trump-mi...

[2] https://www.military.com/daily-news/2025/01/27/here-are-all-...