I don't know why I am bothering to do this....since you were too lazy to read it before.

Interstate Compact/Mutual Aid.  The theory is that, in a state of emergency, States can request Guard units (as well as LE and Public Safety assets) from other States, and said soldiers remain under Title 32 so they are able to be used for active security/law enforcement.  When troops are mobilized under Title 10 (or Title 50 for certain "special" capabilities), the are not permitted to engage in active security/law enforcement duties outside of their State of origin (and even that can get legally dicey under Title 10/Posse Comates).  Therefore, Governors (or the mayor, in the case of DC) can request ANG/ARNG Title 32 support from other jurisdictions.  This is why the first large force of National Guard into New Orleans after Hurricane Katrina was from Arkansas and Mississippi (the biggest LAARNG formation, the 256th EIB, was deployed to Iraq at the time).  Because of Florida's unique climate and terrain (where Blizzards and Earthquakes are the only types of natural disasters we are relatively immune from), Florida has Mutual Aid agreements with almost any jurisdiction crazy/stupid enough to sign one, since it is almost guaranteed that, over time, Florida will require much more mutual aid support than it will ever be required to provide.

Politics aside, it would have been probably worse (for Florida) if DeSantis didn't send them.  Everyone to the right of Nancy Pelosi knew that this was a gross overreaction and/or was done for optics.  Militarily/operationally, it was a very low-risk mission.  Conversely, when the next Andrew, 1926, 1928, or (God Forbid) 1935 Keys Hurricane does a dance on downtown Miami or Fort Lauderdale (or Tampa Bay and/or Orlando), it will make stuff like Charlie and Irma look like a minor Fender-Bender.  The optics will be terrible, and the mission will be anything but low-risk; people will die both during the storm and in it's aftermath, and major aid will take days (if not weeks) to reach the worst affected in it's aftermath.  The optics will be terrible, and Florida will be activating it's Mutual Aid agreements with states as far North as Ohio and as far west as Texas and Oklahoma.  When the nightly news is showing Guardsmen doing "old-school" National Guardsmen sort of things to looters, rioters, etc, a lot of leaders in Blue jurisdictions may be VERY tempted to go wobbly when it comes to sending Title 32 reinforcements, especially if Florida had taken the lead previously in not sending support to their jurisdiction.  If Hurricane Andrew or Katrina is any guide, things will go from "Holy crap, I didn't know it could BE that bad" to semi-Kinetic quick/fast/in a hurry.

It depends; the answer to both questions can be "Yes" or "No" depending on a lot of different factors.  Since it was DC, it may be considered a "De Facto" Federal mission.

Day late, Dollar short

Posse Comitatus doesn’t mean much in DC, since it’s not a state.

Anyone with an IQ of 30 or above knows it was political theater.
They should have stayed home but the queen calls it gets  answered. A fucking clown world we are in.

Do you expect that most Congresscritters are familiar with the US Code?  Most of them couldn't actually even accurately quote any passage from the Constitution or the Declaration of Independence to save their souls from Eternal Damnation!  Besides, it is hard to push the fiction that DC should be a "state" if the MDW requests the 82nd Airborne to come rolling in to 'save the day" from ghosts.

"We have to be fair if we want to be treated fairly."  - said in a lisping Al Franken voice.

Your argument is a rehash of the old Republican bi-partisanship saw.  Fuck.  That.

Laws have no meaning anymore.

Eh, the money printer goes brrrrrrr

I think NH did the same. The governor was not happy with the way the soldiers were treated

Given the way things are going, state governors are going to become more important than the feds, as it's the state governments that are going to have to stand in the gap and tell the feds to take a hike.

I don't think the current federal system is saveable at this point.

Good.

This could be the first victory for the idiot repubs if they'd get their heads out of their asses. All repub governors should follow suite, demand an inquiry. What did Biden know (or not know,) and when? Deprive Queen Nancy the optics and make it the first 'sandal' of the new admin but of course that would be mean and uncivilized right McConnell??

The fucking stupid part for sure....

Having done Hurricane Andrew as a Florida Guardsman and Hurricane Charlie + his three friends in 2004 as AD in an AC/RC unit, plus having a front-row seat in Iraq to the shenanigans involved with trying to redeploy the 256th EIB back to Louisiana from Iraq post-Katrina, I'll see you bet and raise you ,  Any excuse that any Governor with an (R) after their name to short a Mutual Aid agreement will give the Democrats an excuse to do likewise in the future. Based on personal observation/experience, I guarantee that the ghouls in the Democratic Party would have no issue exploiting or even running up the body count in a crisis as long as it was to their benefit (cough "Hurricane Katrina" cough).  

ROE has changed.  Adapt.

IOW, don't expect Dem governors to allow their Guard to help Rep states anymore regardless.

1) Noted  2)  Neither do I; but I am damn sure NOT going to give the dims a ready-made excuse to take a knee while my fellow Floridians suffer so they can play stupid games.