Last week I visited Richard Nixon’s presidential library at Yorba Linda in Southern California, which included a section on his re-election in 1972.

Nixon secured a second term with not only an 18 million majority in the popular vote but a landslide in the Electoral College (EC), taking every State except Massachusetts.

They don’t make American elections like that anymore. And although it’s still widely expected that Hillary Clinton will reach the 270 votes necessary to “win” the EC next week, it’ll still be much more finely balanced than it was back in 1972.

Indeed, now that several polls appear to show Secretary Clinton’s lead narrowing, many Democrats I’ve spoken to hope the EC acts as a sort of firewall between Donald J. Trump and the White House.

As I wrote in my first despatch from the US, it’s a bit like the House of Commons in that it ends up filtering the popular vote and sometimes producing a different result.

If, however, Clinton’s lead holds up over the next few days then the battleground States in which she’s ahead will be sufficient to win the EC, but any further tightening – perhaps if there are more letters from the FBI – could put things in play.

It is, after all, a much more uncertain race than many assumed, and even polling guru Nate Silver now argues that Trump does in fact have a “path to victory”, pointing out that if the popular vote is finely balanced then Clinton could actually lose the EC.

Still, it remains harder for Trump to win than Clinton. The Republican candidate has to take a State or two where he’s currently behind in the polls, which is why he’s recently been campaigning so hard in places like Michigan and Wisconsin.

Earlier this week I was in the New England State of Maine, which Trump has visited five times during the campaign. This at first appears quixotic, but then Maine is one of two States that doesn’t allocate its EC votes on a winner-takes-all basis.

Instead it (along with Nebraska) selects two electors on the basis of its two congressional districts and the other two by state-wide popular vote, which means that Trump could actually secure one elector in this north-western corner of the US.

Importantly, however, no elector is required by federal law to honour their “pledge”. Back in 1972 a “faithless” Republican elector in Virginia chose to give their vote to the Libertarian ticket rather than Nixon/Agnew, and given current GOP opposition to Trump it’s not inconceivable something similar could happen in 2016.

This election also evokes that in 1972 in another respect, in that a lot of voters happen to believe one of the contenders for the White House is, like Nixon, a “crook”.