The contest in Alabama could become the model for the rest of America.

Steve Bannon, the grenade lobbing idealogue who left the White House last month, has set about remaking the Republican Party in his own image. He's now backing insurgent challengers to incumbents who are allied to Mr McConnell and what he sees as a tired establishment intent on blocking the Trump administration’s agenda.

The advert was posted on YouTube yesterday by the Great American Alliance, a pro-Trump grouping which last week appointed a Bannon adviser to a senior role.