If his lawyers are pressing Mueller for his testimony now, because, it will provide Trump the control he wants. Right now, Trump can't control the outcomes with Mueller. He doesn't want Mueller calling on him when he runs for President or untimely in 2018. Trump always wants to believe he is in control and forcing his testimony is his idea of control to ensure there are no trip wires in the political future.
The media on a regular basis states Trump voters are loyal no matter what. There is a reason for that. Most of his constituents are new to politics. I defy the 'establishment' media to know who these folks are by name and power structure.
Under the "W" administration it became easy to receive money for a political organization and file as a 401(d)3. These political pacs began to organize immediately after President Obama won the presidency. It started in Wilmington, NC through "Talk Radio." I do mean immediately. These groups were organized and funded initially by the Kochs. They became known as "The Tea Party," under a variety of names.
They know nothing else. These political pacs have created new millionaires. Does anyone think they are going to give their paycheck up? They will vote for Trump even if he shot someone in the streets. His words, not mine.
The Tea Party political pacs which should also be known as "The Koch Pacs," would lose everything if they lost their ideology to reality. The reason the Republicans have no real policies is because they don't deal in reality, they speak rhetoric as if reality and Trump caught them at it. No one is going to tell me he was so naive to believe the Republicans actually had a health care plan that simply needed to be passed through Congress and signed by the President.
It doesn't matter the reality with the new millionaires. They have found a wagon trans to hitch to and they aren't going anywhere with their ideology or political ambitions. Heck, Trump is their best paycheck. The extremists are their prize. What's his name, Trump's White Supremacist buddy. He wouldn't be where he is without those Koch Pacs. So, he will make his millions and billions no matter the path for the USA.
They don't care. They will go where the USA never should go.