John McDonnell speaks in support of Jeremy Corbyn at Momentum rally

The video discusses Jeremy Corbyn's election as a leader with a significant mandate from party members. It highlights recent challenges faced by the Labor Party, where a small group of MPs is attempting to undermine the democratic decisions made by the party members and the labor and trade union movement.

What does the text suggest about the decisions of the Labor Party members?

What is the relationship between the Labor Party members and the trade union movement as mentioned in the text?