Donald Trump wants to build a border wall. Hillary Clinton wants to keep intact the Blue Wall.

As the general election nears and Clinton’s comfortable cushion has deflated, pundits far and wide are analyzing – and over-analyzing – the Electoral College to determine if the Democrats still have an “Electoral College lock.” This is the Blue Wall of 19 states that Dems count on to provide an automatic 240-plus Electoral College votes, based on the last six presidential elections.

But many who have crunched the numbers say the lock can be picked, and Trump may be the one to knock down the wall.  The 270 electoral votes needed are still within the Republicans’ grasp. Trump retains a small lead or remains within striking distance in battleground states such as Michigan, Pennsylvania, Iowa, Nevada and New Hampshire.

Big shifts

Beyond the current polls, the recent history of the Electoral College presents a rather fascinating geographic look at the big shifts in American politics – in Blue States vs. Red States – starting with Republican Richard Nixon’s election success in 1968 and the 1972 landslide.

After Reagan’s two big wins in 1980 and 1984, and George H.W. Bush’s 1988 victory, the GOP had won five of the last six presidential elections. Political analysts were predicting a “permanent Republican majority” – an Electoral College lock for the GOP. But in 1992, Bill Clinton shattered that myth.

By the time Barack Obama comfortably won re-election in 2012 – and the Democrats notched their fifth popular vote majority in six presidential elections – the new consensus in political circles was that the Dems had established the Blue Wall.

With seven weeks to go until Election Day,  that Blue Wall is showing so many cracks that it perhaps puts Clinton’s hopes of breaking the presidential glass ceiling in jeopardy.

Weak candidates

In each case, these big shifts away from a perceived Electoral College advantage were prompted by ineffective candidates who were inept campaigners. Bush 41 brought the Republican advantage to an end; Al Gore stumbled after Bill Clinton’s consecutive victories and opened the White House door for George W. Bush; and Hillary Clinton’s struggles have provided opportunities for Trump in Blue States and swing states that few politicos thought possible just six weeks ago.

Jeff Greenfield, writing for The Daily Beast, points out that in the lead-up to the 1992 election, the GOP lock included most of New England (far from today’s circumstances)  just about all of the South the plains states and the Rocky Mountain West.

Solid red California?

Here’s where it gets really interesting. At that time, the Republicans had an iron grip on three big states: New Jersey, Illinois and California had gone Republican six straight times. Those are now among the deepest Blue States in America.

As statistician Nate Silver notes, electoral locks are made to be broken. The shifting sands of 2016 have put Upper Midwest states like Michigan, Pennsylvania and even Wisconsin in play, despite their long track record of voting for Democratic presidential candidates. The demographic changes that were supposed to create a “coalition of the ascendant” for the Dems in Purple States such as Virginia, Colorado and North Carolina have not fully materialized.

We’re geographically polarized

Sixteen months ago, in May 2015, Silver warned that political observers should not take the Electoral College for granted. The reason? The country is far more geographically polarized than it once was. And that means Electoral College blow-outs are a thing of the past.

A couple of examples from the numbers-crunchers:

  • President Obama won the 2008 election over Republican John McCain by 7.3 percentage points in the popular vote. That margin yielded 365 electoral votes. By comparison, when FDR won the 1944 popular vote by 7.5 percentage points, he won the Electoral College by 432-99.
  • On the other hand, the last electoral landslide was posted by Reagan in 1984 – 49 states. A lot has changed since then. If Obama had won in ’08 by Reagan’s ‘84 popular vote margin, Republicans would still have won Texas, Tennessee, Alabama, South Carolina, Kentucky, Louisiana, Oklahoma, Arkansas, Kansas, Mississippi, Utah, Nebraska,West Virginia, Idaho, North Dakota, South Dakota and Wyoming — for 136 electoral votes.

It is because of these confounding shifts in the political landscape that Silver’s Five Thirty Eight website issued another caution earlier today about projecting too much with 47 days to go in the campaign. (Clinton’s lead previously shrunk — and rebounded — in June and again in July.)

Here’s their outlook:

Some interested parties are pointing to individual polls as evidence of a Clinton rebound, but a closer look at all the data released over the past three days suggests that those people are stretching.

Yes, Clinton has gotten some good polls. A new Monmouth University survey showing her ahead by 9 percentage points in New Hampshire is a strong result. A SurveyMonkey poll finding her leading Trump by 5 points nationally is good. The NBC News/Wall Street Journal poll putting her up 6 points among likely voters will also warm the hearts of Clinton fans.

But the trend lines are more mixed. … According to (Five Thirty Eight’s computer) models, Trump is still doing better than he was last week. That doesn’t mean he’ll be doing better still next week, but there isn’t yet clear evidence of a Clinton rebound.