Is the President going too far with executive power? It depends on which party you are a member of and which party the President is a member of. Congressional Republicans didn't seem to have any problems with President Bush during the 2000s when it came to executive power. But now are going crazy over President Obama when it comes to executive power. And on the other side Democrats hated President Bush over his use of executive power, but don't seem to have many issues at least that they are raising publicly when it comes to President Obama's use of executive power.
As far as the Southern border and the situation with the immigrant smugglers and the children they brought. It is probably the worst crisis that President Obama has had to deal with at least since the BP oil spill in 2010. But at least he's prepared to deal with it and has already acted on it. And if Congressional Republicans are truly angry about the situation down there and the President's use of executive power and executive orders than they can work with President Obama and Senate and House Democrats to solve the problems down there. Like making sure our security and immigration services have the resources to end the crisis in a responsible manner.