When Donald Trump's criminal trial began, his courtroom entourage consisted of a gaggle of lawyers and campaign aides. This week, it's started to look more like a preview of July's Republican National Convention.

With Michael Cohen, Mr Trump's former lawyer and pivotal witness for the prosecution, on the stand, the number of prominent Republican officeholders in attendance has expanded dramatically.

On Tuesday, Speaker of the House Mike Johnson - the top Republican in the US - met the former president at the courthouse in Manhattan, greeting him with a smile and a nod. Then, while the hush-money trial was still ongoing, he gave a brief statement to the press outside.

"I am disgusted by what is happening here," he said, "what is being done to our entire system of justice."

Mr Trump denies 34 counts of falsifying business records related to a hush-money payment to porn star Stormy Daniels during the 2016 presidential campaign. New York prosecutors are using a novel legal theory to argue that the alleged cover-up amounts to election interference.

Mr Johnson called the trial a "sham" and a "disgrace," said Cohen was a proven liar, and claimed that Mr Trump was being targeted by his political opponents to keep him off the presidential campaign trail as he tries to win back the White House. He even boasted about the size of the crowd at Mr Trump's Saturday campaign rally in New Jersey.

• Live updates - Trump lawyers to question Cohen

It was a dramatic show of support by the man second in line to the US presidency, and it came just a week after Mr Johnson survived a challenge to his congressional leadership from within his own party - a challenge that fizzled, in part, because Mr Trump repeatedly spoke out in his favour.

If the mutually beneficial relationship between Mr Trump and Mr Johnson was on full display on Tuesday, it was emblematic of how intertwined Mr Trump's legal fate has become with the fate of the Republican Party during this election year.

A parade of US senators and congressmen, top Republican officials, and campaign aides trail in behind the former president each morning as a physical show of political unity.