Trump faces off against GOP establishment as he parachutes into contentious Republican Senate primary

It appears that the situation you’re referring to involves former President Donald Trump engaging with the established Republican party in a contentious Senate primary election. This could mean that Trump is endorsing or otherwise supporting a candidate who is not the choice of the party’s traditional power structure. He could be doing this for various reasons such as supporting a more conservative candidate or simply causing friction within the party. If you need more specific details or updates on current events, please give more detailed information.