In these days of secret laws, secret courts and secret prisons, it may seem naive and quaint to consider the rule of law applying to the powerful.
After all, if torture can go unpunished and the president can assassinate people on a whim, then obviously rule of law is only being enforced against the poor and disenfranchised.

Nevertheless, there is a historical need to maintain the illusion of the rule of law.
Without that illusion then the general public can only be kept in check by force alone, and that gets expensive.

Which brings us to the question of Constitutional War Powers and Obama's decision to send ground forces into Syria. Let's forget for a moment that Obama pledged over and over again that he would never do this, and instead consider the question of legal authority.

Legally, however, Obama’s authority to attack ISIS in Syria is on shaky ground. Under the Constitution, Congress decides if and when the U.S. goes to war. In 2002, it authorized President George W. Bush to attack Iraq. That authorization, broadly interpreted, can be read to include the threat ISIS now poses there. But it doesn’t apply to Syria, at least not easily. And the Obama Administration announced this summer that it was no longer using the 2002 authorization to justify its actions.

Instead, the Obama Administration has been using the broad 2001 AUMF written for al-Qaeda to justify the War on ISIS, eventhough the two groups are enemies. At least, they did for a while.

But the administration now says it will also rely on Article II of the Constitution as the legal backing for air strikes against Syrian leader Bashar al-Assad’s forces if Assad attacks the rebel groups.
“If Syrian government forces attack the Syrian fighters we have trained and equipped while they were engaging ISIL, the President would have the authority under Article II of the Constitution to defend those fighters,” a senior administration official told The Hill, using another acronym to describe ISIS...
The Pentagon has refused to say how many groups they are working with in Syria. A diplomatic official close to the Syrian opposition said it used to be about a dozen, but some may have fallen off the list. On Friday, the Central Command spokesman said it was working with a “wide range" of groups.

So we might be going to war against the Assad government, as well as the Russian and Iranian forces backing it, on behalf of unnamed groups, without an explicit AUMF (much less a declaration of war) from Congress.
To say that a shifting legal rational for justifying an ever expanding war sounds questionable is an understatement.

“That means nothing. That’s pretty bad when you have to cite Article II…You have to be more specific than that,” said Louis Fisher, scholar in residence at the Constitution Project and former Congressional Research Service researcher.
He and other legal experts say Article II has been interpreted to allow a president to “repel sudden attack” against U.S. troops, the U.S.mainland, and its interests.
Using it to defend Syrian rebels would not fit under that previous interpretation, he said.
“Invoking Article II is question-begging,” agreed Stephen Vladeck, law professor at American University.
Vladeck said Article II has also been interpreted to allow the U.S. to defend its “assets.”
However, he said “by that logic any person or piece of military equipment used by anyone on a side of a conflict with which we agree is all of a sudden covered by Article II. And that cannot be right.”
As recently as last month, Marine Gen. Joseph Dunford, the incoming chairman of the Joint Chiefs of Staff, told the Senate Armed Services Committee that the U.S. did not have the authority to conduct airstrikes against the Syrian regime.
“My understanding is that we don't have the legal authority at this time to go after the Assad regime. And it's also the policy of the administration not to go after the Assad regime militarily,” he said at a hearing on July 7.

The Obama Administration has already completely rejected the War Powers Resolution.
Even the Washington Post has questioned if Obama has legal authority for this war.

The only document the White House has provided to a few key lawmakers comprises four pages of what are essentially talking points, described by those who’ve read them as shallow and based on disputed assertions of presidential authority….
In his secretive and expansive view of presidential powers, some experts see Obama following the lead of his predecessor, George W. Bush.

If the rule of law still applied to the United States today, this would be a big deal. In fact, it would be a Constitutional Crisis.
Which is ironic because Obama was a lecturer in constitutional law at the University of Chicago, who once said, "The President does not have power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation."
Good thing for Democrats that we are in a post-rule of law world.