On Sunday morning, West Virginia Senator Joe Manchin dropped a bombshell on his fellow Democrats. On the stridently pro-Republican Fox News TV channel, no less, he declared he will not support President Joe Biden's cornerstone Build Back Better $2 trillion social spending bill.
This forces a reshuffling of Democratic priorities. Mr Biden appears to have anticipated this fiasco, given his sudden emphasis on election protection last week.
He has sought to present Democrats as a party that is serious about governance and secures deliverables for the American people. That pitch is badly damaged but hardly eliminated. Early in his administration, Mr Biden secured a $1.9 trillion pandemic relief package, and in November added $1 trillion in badly-needed infrastructure spending.
But all year, many Democrats dreamt of sweeping, transformational social legislation. It was at best unrealistic and at worst sheer hubris.
Last year Mr Biden defeated Donald Trump soundly, but the Democrats retained a very small majority in the House of Representatives. And only two stunning victories in Georgia for both of its Senate seats provided Democrats a de facto Senate majority: 50-50, with Vice-President Kamala Harris empowered to cast the deciding vote in the event of a tie.
This left no wiggle room, since they cannot afford to lose a single senator on any vote. It is hard to regard this as a broad mandate for transformational legislation.
Internal divisions still run deep. Democrats from northeastern states demanded the restoration of a generous cap for State and Local Tax Deduction, a regressive measure that would mainly benefit their better-off and wealthy constituents. The rest of the party eventually capitulated.
An even more obnoxious conservative faction of at least two senators, led by Mr Manchin, voted for the pandemic relief and infrastructure bills but did not negotiate in good faith with Mr Biden. Warnings from the party’s most liberal faction that, shortly after the passage of the infrastructure bill, Mr Manchin would simply kill social spending proved correct.
Mr Biden has been operating on the assumption that Americans mainly want deliverables from government and that securing benefits would be rewarded, even in the 2022 midterms. Mr Manchin’s bombshell probably rules out any additional major spending before next November's election.
Yet Mr Manchin has given Democrats little choice but to focus on protecting elections and constitutional processes from a co-ordinated attack, which is surely more important and urgent.
Mr Biden had already pivoted.
Last week at South Carolina State University, he implied that preventing efforts to undermine the constitutional system is now his priority. "I've never seen anything like the unrelenting assault on the right to vote. Never," he said, pledging strong support for two pending bills that would block scores of new state laws making voting more difficult and even pointless.
Democrats have been fixated on blocking new obstacles to voting. Thirty-three states have enacted measures restricting, complicating or limiting voting. Some criminalise common efforts to help voters through translation, transportation or even providing water to those waiting in endless lines.
But far more nefarious are efforts by state-level Republicans – animated by the shameless lie that Mr Biden only won because of widespread fraud – to rewrite election rulebooks and shift authority from bipartisan or nonpartisan institutions to entities and individuals that have clearly signaled a willingness to distort the process, and even cheat, rather than lose.
Mr Trump created this template after his defeat by seeking to overturn the result by any possible means. He was effectively probing American institutions for weaknesses and identified many.
He tried to get state-level officials to change the result by suddenly "finding" new votes for him. He failed, partly because results had already been formally certified by the states. He may still fantasise about "decertifying" the 2020 results, but there is no provision for that in US law.
That could change. The Arizona legislature is seeking the power to revoke the state's certification of election results at any time before the presidential inauguration.
Mr Trump pressed Republican legislative leaders in states he lost to simply ignore the results and send alternate, unelected, electors to the electoral college, giving him a win.
He failed but from this arises a co-ordinated operation to implant pro-Trump election deniers and conspiracy theorists into key election positions to potentially allow Republicans to commit their states to a losing candidate.
These state-level Republicans are trying to ensure that next time, Mr Trump or another political fraud can succeed. They are establishing the kind of undemocratic partisan authority over election results that Mr Trump demanded last year, but which did not exist.
And there is the partisan gerrymandering I described in these pages last week, which, in several swing states, effectively locks in Republican state legislative control.
Mr Trump’s final gambit – armed with numerous coup-plotting memos by his advisors and officials, some involving military intervention – was to unleash a violent mob on January 6 to attack Congress and try to prevent ratification of the national election outcome.
Mr Biden may have been misguided all along to focus on securing deliverables for a people whose basic institutions are being brazenly hollowed-out.
Yet to protect US democracy, he will again confront the same Democrats, led by Mr Manchin, who killed the Build Back Better legislation.
Democrats will have to unanimously agree on establishing a carve-out to the filibuster rule that allows election issues, like budgetary matters, to pass by a simple majority. And, given nation-wide Republican shenanigans, it is imperative they add language that clearly establishes under federal law that state legislatures do not have the power to overthrow valid votes and election results under any circumstances.
These Republican anti-democratic measures are the logical follow-on to the anti-democratic insurrection at Congress that sought to sabotage the ratification, according to law, of Mr Biden's victory and prevent a peaceful transfer of power.
Protecting the US Constitution and democratic system is not optional. It is essential and urgent. Democrats appear to be the last ones left who can halt and reverse the US slide towards a grim parody of democracy.
Mr Manchin has pointed his fellow Democrats clearly in that direction and the pressure on him to become part of the solution this time should be enormous. It’s one thing to block spending, but quite another to blandly decline to save the constitutional order from mortal peril.