Barack Obama has said Donald Trump is unfit to be President in his most resounding criticism yet of the Republican candidate. In a strongly-worded statement, Obama said Trump - who he couldn't bring himself to name - was 'woefully unprepared' for the top job. Obama's intervention is extraordinary and it's difficult to think of a precedent for a sitting President condemning in such terms one of the frontrunners who could replace him. But whilst Obama fans will cheer from the sidelines, in reality his decision to wade in won't help.
Firstly, it will make it harder for any Republicans to now withdraw their endorsements of Trump. If they were to in the aftermath of Obama's statement today, it'll look like they are doing the President's bidding - and that won't go down well with party supporters. So whilst a raft of key Republicans, including congressman Richard Hanna, had earlier said they would not vote for Trump, after Obama's comments those with similar thoughts may be somewhat more reluctant to now voice their opposition to Trump.
What's more, it's worth remembering where Trump draws his support from. You can say a lot of things about Donald, but at his most basic, he's the 'change' candidate. He successfully made it through a packed Republican crowd largely because he offered something different from the establishment. And many of those backing Trump are doing so because they want a switch from the status quo, having become increasingly alienated under Obama's Presidency. So in deciding to criticise Trump, in reality Obama could end up achieving the opposite effect and consolidating the Republican nominee's support.