Despite a strong first 100 days in office, most notably securing the massive pandemic relief bill, migration has emerged as a major vulnerability for US President Joe Biden.
His exposure on this is worse than anticipated, and comes from the left as well as the right, as a chaotic set of reversals last week regarding refugees amply demonstrated.
Following the November election, Republicans settled on border and migration issues as the focus of their campaigns for next year's crucial congressional midterm elections.
Anti-immigrant rhetoric is a mainstay of the new, Donald Trump-influenced, nativist Republican orthodoxy. And they lack many other avenues of attack, especially since Mr Biden managed the vaccine rollout superbly – already all adults are eligible for vaccination – and this year's economic performance is forecast to be the strongest in 40 years.
Nonetheless, migration looks like a more potent issue than even Republicans had hoped. The refugee quota reversals last week underscore the administration's anxiety and uncharacteristic confusion on migration issues.
One major problem is that most Americans, including many politicians and mainstream media commentators, incorrectly but consistently conflate three distinct issues: undocumented or unlawful migration, asylum seeking and refugee entry.
Refugees are typically conflated, explicitly or implicitly, with asylum seekers, who, in turn, are generally equated with undocumented migrants.
Refugees make their case for entry based on persecution from when they already are. Asylum seekers request similar protection but at the border. Though many otherwise-informed Americans don't seem to understand this, coming to the border unannounced and requesting asylum is not unlawful.
Under former presidents Barack Obama, and especially Mr Trump, measures were enacted to compel asylum-seekers to return to their own countries or third countries such as Mexico, while their cases are reviewed. Given the pandemic, virtually no adult asylum seekers are being allowed to remain in the US pending adjudication.
Under US law, however, unaccompanied minors cannot be summarily expelled to an uncertain fate. Instead they must be protected and placed with relatives or foster families until their cases are resolved through a usually lengthy process. Under Mr Trump and now under Mr Biden, there were several surges of families and especially unaccompanied minors requesting asylum at the Mexican border.
Last fall, the Trump administration was quietly bracing for another major surge at the beginning of this year, based on ongoing economic and crime crises and severe hurricanes in Central America, and predictable seasonal fluctuations.
But because Mr Biden won, he inherited this problem, and his pro-immigration rhetoric and promised policy changes may have helped promote the current surge of unaccompanied minors seeking asylum.
Certainly Republicans are stridently blaming him for what they are inaccurately describing as "the worst border crisis in history", but which is clearly a big problem.
Many of Mr Biden's conservative or Republican sympathisers, particularly in the American media, have been urgently warning that this is likely to be the most powerful Republican weapon against him. The biggest concern is that his control of Congress is razor thin, especially in the equally-divided Senate, but also the House of Representatives.
Historically, new presidents' parties suffer significant setbacks in their first congressional midterm. Next year, Democrats cannot afford to lose ground in either chamber, especially not the Senate.
Bucking that historical trend is Mr Biden's primary political task right now. That helps explain why in the past three weeks his administration changed its tune at least six times on refugees.
Technically, refugee acceptance is not related to border control. Refugees apply over a long process from outside the country, have convincingly demonstrated past, or a well-founded fear, of persecution and are thoroughly vetted and approved before entry.
But Americans tend to think of refugees and asylum seekers as synonymous, and then often even equate both with undocumented migrants who skirt the law altogether.
Many Americans, following Mr Trump's lead, are categorically opposed to almost any immigration from non-white countries.
All migration is now effectively refracted through a lens of overriding panic on the Republican right about demographic racial and ethnic transformation, and a perceived loss of status and power among white, Christian Americans.
From this perspective, details don't matter. It is simply and by definition objectionable and alarming for more non-white people to enter the country.
Some rightists, encouraged by the stridently white nationalist FoxNews TV host Tucker Carlson, are increasingly describing even lawful immigration as a Democratic plot to dilute the votes of white Americans by adding "slavish," "servile" non-white immigrants. It is, they absurdly insist, a “voting rights” issue.
This is an only slightly encoded reiteration of the racist "great replacement" conspiracy theory that liberals, especially Jews, are attempting to overwhelm traditionally white-majority societies with immigrants from Asia, Africa and Latin America in a plot to “destroy Western civilisation”.
This escalating mania is the context and subtext of the current controversies.
Mr Biden campaigned on reversing Mr Trump's near zeroing out of refugee acceptance, pledging to increase from a mere 15,000 to 125,000 annually.
But following the border crisis and related Republican attacks, he overruled his own officials and decided to stick to 15,000 for 2021.
That produced an immediate, massive outcry among Democrats. The left was infuriated and even some of the President's closest allies complained bitterly.
Mr Biden has proven unexpectedly popular with progressives, but not enough to get away with maintaining Mr Trump's anti-refugee policies.
Within hours he pledged to accept over 60,000 this year instead, but the official change is pending. Mr Biden was clearly caught off guard and lacks both a political and practical plan to deal with this incendiary issue.
Smelling political blood, Republicans feel vindicated in making migration their primary campaign issue, with pandemic mitigation like school closures a distant second. If the President continues to score victories on controlling the pandemic and reviving the economy, the Democrats should survive migration-based attacks and do well in the midterms. But their exposure is evidently significant, particularly if other failures emerge.
Mr Biden has had an excellent first 100 days, but as he seems to understand, he's quite vulnerable on migration and border issues. He urgently needs better policies and, especially, messaging to protect his paper-thin Congressional majorities next year.
Hussein Ibish is a senior resident scholar at the Arab Gulf States Institute and a US affairs columnist for The National