Should Congress formally declare war against Radical Islam and its supporting states?

It is my understanding that Congress already has in 2001. Its called the "war on terror"; war against an unknown, unnamed enemy in any location of the world for an indefinite period of time. This is and has been justification for the many recent years of US involvement in the Middle East and many Domestic actions by Dept of Homeland Security (DHS). I don't think the general public is aware of the War on Terror's far-reaching Domestic implications. Politicians are, make no mistake. It's basically a globalist policy that shelves the US Constitution (4th amendment rights, privacy, due process, etc.).
Currently, Trump pulled troops out of Syria without Congressional approval. Hawkish Congressmen are up in arms over it (no pun intended) however, Senator Rand Paul has called them on it and said, Hey, if you want our troops in Syria, then go to the Capital and vote for a Declaration of War. That sounds like the American Way to me.

Declaring war entails much more than conducting combat operations. For one it tells our enemy that we are deadly serious about defeating them. It also gives us legal authority to take certain actions that we couldn't otherwise, both domestically and overseas. Taking this action and fighting a total war will result in a shorter war with fewer casualties than the half-ass effort we are conducting now. Eventually we will have to take on a nuclear Iran anyway.

It is always a better option to declare a war on a political organization than to declare one on an ideology. ISIS is very adept at fighting using insurgency tactics and if we want to win against an insurgency then we need to adapt our strategy to fit the intended conflict. It's more than Congress declaring war on ISIS that needs to happen/change, policy needs to be adapted as well. You can't go against an insurgency while your hamstrung with political correctness.