Looks like Joe Biden might be a legitimate front-runner after all. At least that’s the assessment from Biden’s opponents who have watched his post-launch polling bump with increasing levels of panic. The Hill reports that progressive activist groups have begun shifting strategy to specifically target Biden, hoping to boost Bernie Sanders in his stead:

Progressives are taking shots at Joe Biden, seeking to blunt the former vice president’s rise in polls by arguing he is too conservative to be the party’s presidential nominee.

The criticism has come from rivals to Biden on the campaign trail as well as liberal groups seeking to put a dent into his poll numbers.

They are casting Biden as an establishment figure out of touch with the grass roots of his party, highlighting his work on a Clinton-era crime bill and the Iraq War, among other issues.

The criticism suggests some angst on the part of progressives, who fear Biden might beat out candidates such as Sens. Bernie Sanders (I-Vt.) and Elizabeth Warren (D-Mass.), who have more liberal voting records than the former vice president.

Who would have guessed that the two top candidates in a party immersing itself ever more in identity politics would be two white male septuagenarians? And yet here we are, in poll after poll, with Biden way out in front of Bernie, and Bernie way out in front of everyone else. The latest tracking poll results from Morning Consult show the dramatic differences between the Biden-Bernie level and the Everyone-Else level:

The two lines in purple and light blue that briefly appear above the 10% line belong to Elizabeth Warren and Kamala Harris, respectively. No other non-Biden/Bernie Democrat in the field has polled above 10% at any time this year, and it’s been almost two months since either Warren or Harris exceeded that threshold, too. In this graph, it’s pretty clear that none of them have been hurt by Biden’s official entry either; Biden’s getting his bump almost entirely at Bernie’s expense.

But that’s just one polling series, some may object. True, but take a look at the dynamic from aggregated national polling at RealClearPolitics:

The only interesting difference between Morning Consult and everyone else is that Warren never hit 10% in the aggregate average of polls. Only Harris has made a move out of the second division, and then only briefly.

With the polling graphed out, it’s pretty clear why progressives have hit the panic button. The longer that upward arc goes for Biden, the more donors will conclude that his nomination is inevitable. That will force out a number of other candidates whose departures might benefit Sanders or Harris by consolidating the left wing against Biden, but it makes them more vulnerable to a lack of talent, too. Harris so far is turning out to be a mediocre presence on the campaign trail despite initial high hopes for her ascendancy, perhaps because having six or seven of her Senate colleagues in the race has drained her bid of any special attention.

Normally, one would presume that Biden would do enough damage to himself that such internecine opposition tactics could be avoided. At least so far, Biden seems able to govern his tongue effectively enough to keep it from cushioning his foot from his teeth. That will only last so long, and if the field hasn’t consolidated by that time, Biden might not get very friendly treatment from media outlets that might otherwise cover for him in a general election. Even that threshold might come a lot sooner than one would predict if the polling trends continue in the direction we have seen for the last few weeks.