How fast would America come together and get its act together if North Korea dropped a bomb on us?

North Korea hasn't been in a war for over 30 years. They are not likely to nuke anyone, yes those stupid tests are annoying, but they would have hit something by now and called it an accident if they truly wanted to start a war and have China, Russia, etc. back them. In my view, America has gone overboard with making nuclear warheads, this was done at the start of the Trump administration because 'Russia had too many'. If at any given time Russia has I guess one to two thousand more warheads then us, what difference does that make as if we started bombing each other with all of them the earth would be obliterated, so again, Russia making more becomes subjective. What I'm saying is the white elephant in the room is that North Korea is like a Garden Shed next to Oprah's Mansion in terms of capability. I think we bullied them for too long and should just leave them alone. I'm not going to sugarcoat it, North Korea should be able to have nuclear weapons, its like legalizing prostitution, let them have their nukes and overnight they will stop tests and accept foregin aid for those poor starving people, they would have no reason to threaten people if they couldn't veil the East in the US's hypocrisy is what I mean. This is what we are blind too.

Sleep well Skippy the Missile would never see US soil.

I assume you are talking about regular bombs like a Pearl Harbor attack. The country won't come together. People will just focus on the location of the attack being in a blue or red state. 

It would be too late. Once the Nth Korea bombs you and then China will sent it nukes towards you, follow by Russia and Iran. The U.S will be a complete goner to the ashes.

If that happened democrats would blame President Trump, and give NK billions of dollars.

That is not within the realms of reality. Days of nuclear or atomic bombs dissipated long ago when we ceased being the only one with it. 

If it of the magnitude that requires the approval of Joe Biden, it would take at least a couple of weeks.  Joe is not capable of making such a decision, and you would have to remove him and put in Harris.  There is no telling what she would do.  She was the least liked democrat presidential candidate for a reason.   Her purpose is be such a poor alternate that an incapacitated Biden is still better than Harris.  

In about 3 months.