Is the USA Now Under God's Judgement?

In a nutshell:

Reformation Papacy

The institution of the papacy underwent attacks by many Protestant reformers, including Martin Luther (Pope Leo X was the pope who planned the initial church reaction against Luther until his death in 1521), John Calvin, Thomas Cranmer, John Knox, Cotton Mather, and John Wesley, identified the Roman Papacy as the Antichrist.[citation needed] The Centuriators of Magdeburg, a group of Lutheran scholars in Magdeburg headed by Matthias Flacius, wrote the 12-volume "Magdeburg Centuries" to discredit the papacy and identify the pope as the Antichrist. The fifth round of talks in the Lutheran-Roman Catholic dialogue notes,
In calling the pope the "antichrist," the early Lutherans stood in a tradition that reached back into the eleventh century. Not only dissidents and heretics but even saints had called the bishop of Rome the "antichrist" when they wished to castigate his abuse of power.[1]
The four most important traditions to emerge directly from the reformation were the Lutheran tradition, the Reformed/Calvinist/Presbyterian tradition, the Anabaptist tradition, and the Anglican tradition. Subsequent Protestant traditions generally trace their roots back to these initial four schools of the Reformation. It also led to the Catholic or Counter Reformation within the Roman Catholic Church. Lutherans, Reformed, Anabaptists, and Methodists all included references to the Papacy as the Antichrist in their confessions of faith:

As to the rest...
First it should be pointed out that holding a “discourse” with them is not the same as saying that all is well and good with their beliefs. Remember that Luther was even a Catholic Monk, and was holding discourse with with the Church in an attempt to reform it. He had no intention of creating the schism that occurred due to the Papacies unwillingness to adhere to the Word of God. The 95 thesis are actually written in a manner which shows Luther at the time believed that the Indulgence sellers were using tactics that the Pope would disagree with. The problem was that the Pope not only didn't disagree with what they were doing, but was pushing them to get even more money.

Anyhow...
I can speak for at least one of these groups you have mentioned here, the others I am not as up on their history. I can tell you though, that one of the things I believe I already mentioned is that most Churches now follow Jesuit Futurism, rather than the Historicism that their founders originally wished. There is a reason for this, and remember that it was the RCC's intention to ensure this happened in all protestant churches, as it was part of the counter-reformation.

I can tell you that the ELCA was founded by a number of ex-members of the LMCS and WELS. These were folks who excommunicated from the two churches after getting involved in the Charismatic Movement. Its comprised of independent Churches (each pastor owns his own church), with no strict oversight like you have with the LMCS or WELS.

Evangelical Lutheran Church in America
In 1976 the Association of Evangelical Lutheran Churches (AELC) was formed from congregations that left the Lutheran Church - Missouri Synod in a schism precipitated by progressive-traditionalist disputes over higher criticism, academic freedom and ecumenism. Its establishment was precipitated by the Seminex controversy at the LCMS's Concordia Seminary in St. Louis, Missouri in 1974. The AELC brought approximately 100,000 members into the ELCA. Its immigrant heritage came mostly from Germany; the complexion of its theology generally resembled that of the LCA, as the dissenting former "moderate" faction of the LCMS.

This groups is what became the ELCA...

Differences within the ELCA
The ELCA has many differences of opinion among its constituent congregations, which have caused a number of disputes over social and doctrinal issues. In part, this is due to the fact that it assimilated three different Lutheran church bodies, each with its own factions and divisions, thus inheriting old intra-group conflicts while creating new inter-group ones. Differences on issues usually reflect theological disputes between various parties.

So this is why we get all sorts of whacky, anti-Lutheran stuff out of the ELCA. When you see something that the Lutheran Church has done, and its in some way contradictory to Christianity, you can bet that its the ELCA that’s doing it, not the LMCS or WELS...
I can tell you right now that both the LMCS and WELS consider the Papacy the office of the Antichrist...

Wisconsin Evangelical Lutheran Synod
In 1959 the WELS formally issued its Statement on the Antichrist, a doctrinal statement that declared, "we reaffirm the statement of the Lutheran Confessions, that 'the Pope is the very Antichrist'".[21] This identification of the Antichrist with the Pope is part of traditional Protestant amillennial historicism.[22] [23] [24] The Roman Catholic Church is also amillennialist, but, unlike the WELS, holds to the view that the Antichrist will come near the end of the world. Mark Schroeder, president of WELS, affirmed in 2011 that "WELS does hold to the historic Lutheran position that the Roman Catholic papacy fits the biblical characteristics of the Antichrist." He also stated that "While WELS continues to see the characteristics of the Antichrist in the Roman Catholic papacy, it is wrong and dishonest to portray this belief as stemming from anti-Catholic bigotry. We do have strong convictions, and we identify what we believe are teachings that depart from the Word of God. But we hold no animosity toward Christians who hold the Roman Catholic faith, and we respect the right of people to hold beliefs different from ours even as we point out the error. Furthermore, we rejoice that even in the Roman Catholic Church, where we believe that the gospel has been distorted, there are many Catholics who hold to a simple faith in Jesus Christ as their Savior and who will ultimately be saved. Testifying to the errors that still exist in Catholic doctrine is itself an expression of love; remaining silent or glossing over doctrinal differences would express the opposite."[25]

Lutheran Church Missouri Synod
Antichrists
The LCMS holds that all "false teachers who teach contrary to Christ's Word are opponents of Christ" and, insofar as they do so, are anti-Christ.[17] The LCMS does not teach, nor has it ever taught, that any individual Pope as a person is to be identified with the Antichrist.[17] However, to the extent that the papacy continues to claim as official dogma the canons and decrees of the Council of Trent, the LCMS position is that the office of the papacy is the Antichrist.[17]

Could the Lutheran, or other protestant, churches re-merge with Roman Catholicism?
Sure if the RCC agrees to submit on all its Anti-Christian and Anti-Biblical stances...
Never going to happen though.