Donald Trump has dismissed a proposal from a key ally in Congress that would end the longest US government shutdown in American history, declaring that he would "never ever back down" over border security.. Twenty-four days into the partial shut down, Mr Trump rejected the idea from Republican Senator Lindsey Graham. The Senator had indicated he discussed the option of reopening the government temporarily as negotiations continue with Democrats over their refusal to sanction a demand from the president for $5.7bn to build a wall on the US-Mexico borer.