Well according to the first amendment:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech,
or of the press;
or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
Trump's move could be interpreted as prohibiting.
But this is a republican party event that is nothing to do with Congress so it is unlikely that rules that only apply to decisions made by Congress are applicable for this particular event.
Thats a good point. I never thought of that.
You are both conflating two issues that are only tangentially connected. You are both right and wrong in equal measure!
The key point to take away from the First Amendment is that the Constitution guarantees the freedoms of religion, expression, assembly and the press. Under no circumstances at all should those freedoms be abridged or prohibited.
There is a tension within the Constitution as to what body is the ultimate arbiter of law within the US; is it the Congress, the Supreme Court, the Executive (the President) or the "States Assembled in Convention". To make it crystal clear, the Framers of the Constitution explicitly said that
should not make any law that restricted or prohibited those freedoms. Put another way, the Framers believed these Freedoms were so important that nobody should challenge or change them
everybody had a say in the process. This means that if the Congress wanted to challenge or change them, they would then have to be put before the individual States to be voted upon in turn ("States Assembled in Convention").
In this instance, nothing has changed. No law has been passed by the Congress to hinder or prohibit the press. The press are still, by law, permitted to attend. However, the GOP has decided that there is no need for the press to attend this year's convention. There is an ongoing public health crisis and it would be irresponsible to risk exposing individuals to Coronavirus. By that standard, @Ne1L C is correct. The decision taken by Trump and the GOP could be seen as an affront to, and a clear breach of, the First Amendment.
Where @AlexS is correct is that this is a GOP event. They get to write the rules. The basic rules that everybody abides by, ie. the Constitution, still apply to them, but there is a bit of latitude at the present time. It's very much a case of "let's not make a bad situation
worse by having the world's press descend on Charlotte, NC in the middle of a pandemic".
For what it's worth, I don't see a problem with it. It will be live-streamed. It is no different to a pooled event with one camera, one photographer and one journalist sharing copy. Journalists have never had the opportunity to question the candidates at a nominating convention. This year's conventions will be no different. Nothing has changed.
To return to the legal tensions within the Constitution, the nominating conventions are not mandated by the Constitution. However, other forces - such as Federal campaign finance laws, the rules set out by either the Commission on Presidential Debates or the Federal Election Commission, or the laws of the individual States - mandate that a convention is held. This means that it would be difficult for the GOP and Trump to remove the Press in its entirety from the process. When something is required by law (a convention), other laws that protect the rights and roles of other entities (freedom of the press) automatically becoming a concerned party.