WHY TARGET DEMOCRATS?

Trump has made it quite clear that he is trying to extort funds for his border wall by wresting children away from their parents and blaming the Democrats for not coming to the Republicans to  beg to remedy the situation.  Democrats fail to see why the Republicans just don't get their fellow Republicans to vote the funds since they have majorities in both Houses of Congress.  Trump supporters claim that this is disingenuous on the part of the Democrats as they are perfectly aware that there are insufficient Republican with any humanity to be moved by the sight of terrorized children losing their parents.