Trumpsters seem to have the memories of Dory from Finding Nemo. So, to refresh ..The Senate, in December, passed a clean spending bill that Pence told them the Orange diaper baby would sign. Maan Coulter and Rush Limpballs didn't like that so they attacked Trump and Trump caved to radio hosts, refusing to sign a clean bill.
When the government reconvened, Trump told Pelosi he wanted a wall or he would be "proud" to shut down the government (also known as extortion or hostage taking). Pelosi refused to negotiate with a hostage taker...which is the official position of America.
Trump: Proud to shut down government over wall - CNN Video