Let’s pick up where we left off last week.

Joe Biden, the Democrats’ 2020 presidential candidate, rightly says he’d be “the most progressive” — read: liberal — president in American history.

That understates the point in at least two ways.

First, he’d likely be even more liberal than any major-party nominee.

Second, it’s not just he. On the ascendancy in his party are those who sound less like many leading Democrats of decades gone by and more like European socialists, and who appear not to understand, much less believe in, American exceptionalism or the greatness of Western civilization.

No major party has ever moved this far left.

As a result, many identify with Democrats less than they once did. This isn’t new. Decades ago, Ronald Reagan, once a Democrat and a union leader, became a Republican. He said he didn’t leave the Democrats. They left him.

Meanwhile, President Trump has reached out to, and encouraged into the Republican fold, many Americans who have rarely or perhaps never voted at all, or have rarely or perhaps never voted Republican.

The president has done this in part by pursuing policies that some other Republicans haven’t pursued.

The upshot is that the two major parties’ 2020 presidential candidates contrast sharply in many significant ways. That’s why this presidential election matters. It really matters.

When has the contrast ever been greater? Or at least more consequential?

Among foreign-policy issues are trade, terrorism, our allies’ contributions to alliances, and the importance of defending our vital national interests around the globe without being the world’s police department.

Among domestic issues are the federal courts, particularly the Supreme Court. The president has thrice kept his promise to nominate originalists, not activists, to the high court.

Also among domestic issues are jobs, taxes, regulations, the current pandemic, health insurance, border security, including the border wall, and the swamp, including the deep state.

Make no mistake. Many in the bipartisan “Repucrat” and “Demoblican” swamp resent not only the president but also those who elected him.

Another domestic issue has presented itself in 2020: Law and order. By and large, 2020’s rioters — who aren’t mere “protesters,” as some opponents of the president assert — resent the president too. “Make American Great Again” garb isn’t exactly prevalent among them.

All of which brings us to the election itself.

One challenge to the president’s re-election is the — let’s understate this point — incorrect statements that his opponents, including those in the national press, repeatedly make about him. But the public in general is smart enough to understand the repeated refutations.

Another challenge is the economic consequences of the current pandemic. But the public in general is smart enough to understand that but for the pandemic, and the shutdowns perpetuated by the president’s opponents — neither of which are the president’s fault — the pre-pandemic prosperity would be fully continuing.

Yet another challenge is easy to meet in that it’s fully under the president’s control. As this column’s July 2020 open letter to the president explained: Although this election is the president’s to win, he must stay on message, and but for unforced communication errors, the president’s re-election may well have been a cinch, given the administration’s accomplishments.

Not that he read the letter, yet in recent months, he has largely stayed on message, just as he did in 2016 as Election Day approached.

Another challenge could become the greatest one. To win, the president and his team must overcome efforts to undo a victory, including, but not only, with unsolicited, mail-in — as opposed to solicited, absentee — ballots.

Hillary Clinton, the president’s 2016 Democrat opponent, says Biden shouldn’t concede under any circumstances.

Details are emerging of how she, her campaign, the deep state, and the previous administration, in which Biden was vice president, have targeted Trump and others, both during the 2016 campaign and since.

The president and his team already understand they need to look out.

Dr. Randy Elf’s July 2020 open letter to the president is at https://www.post-journal.com/opinion/local-commentaries/2020/07/stay-on-message-mr-president and https://www.observertoday.com/opinion/commentary/2020/07/dear-mr-president-stay-on-message.

COPYRIGHT 2020 BY RANDY ELF