As a patriotic American, I afford a certain measure of respect to the (presidential) office even if I'm not overly fond of the person currently holding it (which is usually the case). So I'm not going to go taking cheap-shots at the president, whoever it may be (which is different than offering valid, policy-based critiques for constructive purposes).
That said, it is becoming steadily more obvious that President Biden's cognizant capacities are diminishing. I'm not saying that to be mean. Not lampooning a man for aging and facing mental deterioration. Those of you who do that or disrespect the office by throwing around uncouth terms like 'Sleepy Joe' should be ashamed. Such unbecoming discourse reflects poorly on those who use it and upon our nation itself.
However, "the president's declining cerebral functionality" is a valid, legitimate concern for a responsible citizen. Before someone starts with "Yea well the alternative is etc. etc. etc." just don't. I'm not endorsing anyone, merely pointing out that, perhaps, Democrats should consider nominating someone else and President should consider discreetly stepping down. There's no dishonor in not pursuing a second term. In fact, some of our best presidents did just that.
James K. Polk may have been a nationalistic, warmongering mad-man, but he's technically the only president we've ever had who fulfilled all his campaign promises. So, say what you will about his terrible manifest destiny policies, the guy was an effective executive. But he didn't pursue a second term because he promised not to. I applied that decision, at least.
James Buchanan was a pretty terrible and especially ineffectual Commander in Chief. But, in my opinion, he wasn't our worst (as many historians like to argue). Why? Because he at least had the dignity to realize he wasn't any good at the job and step aside for someone else. Unlike his predecessor (Franklin Pierce) who disgraced himself and his party by making them nominate someone else (only time a sitting, elected president lost his party's primary nomination).
Same goes for Andrew Johnson. He had a lowkey God-complex but he still had the sense to know he wasn't popular enough to win in 1868.
Rutherford B. Hayes, another underrated president, followed in Polk's footsteps by promising to serve only one term and sticking to his word. He left the White House in fairly favorable standings and could have easily been reelected. But he stepped aside for another with dignity, unlike his successor's (James Garfield) Vice President (Chester Arthur) who followed Pierce's path by forcing his party to reject a sitting executive which opened the door for the first Democratic President (Grover Cleveland) in twenty-four years, a devastating blow to decades of Republican power in 1884.
Calvin Coolidge was an enormously popular president, perhaps the most popular not to seek a second full term. In fact, Silent Cal may have been one of the ONLY people who didn't want a second four-year Coolidge Administration. When he announced his intentions to step aside, national outcry ensued with protests, petitions to "Draft Cal," and inner-party schemes to nominate him in the primary whether he liked it or not. Unmoved, Cal shot down all such efforts, reasoning, "No man should spend more than ten years in such a position of power." Such is the trademark of great leadership. Not the ability to seize power, but the ability to reject it. Again, his less popular successor (Herbert Hoover) had trouble with this and forced his renomination, opening the door for five consecutive Democratic victories, including four for Franklin Delano Roosevelt who didn't share Coolidge's ideas about staying in power too long.
Franklin Roosevelt’s successor Harry S. Truman found himself in a similar pickle in 1952. He famously upset the favored Thomas Dewey in 1948, spurring an embarrassing tide of editorial retractions that predicted his loss. But by 52, his handling of Korea rendered him even less popular. So he stepped aside with dignity. It's worth noting that President Truman was exempt from the recently passed Twenty-Second Amendment that imposed presidential term limits. He could have been the last president to serve more than ten years. But he opted out of his own grandfather clause.
Lastly and most recently, we have Lyndon B. Johnson and, if there's anyone from whom Biden should draw particular inspiration, it's LBJ. The nation was wary when Johnson took over for the popular young John F. Kennedy (much like the dynamic between much-loved Barack Obama and less popular Uncle Joe). But he won over the nation by standing up for civil rights and pursuing a (popular during his first term) path of interventionism against communism in Vietnam. Unfortunately for Johnson, that whole Vietnam thing didn't age very well and a once-supportive nation turned its back on him once things started going south. It's not entirely unlike what's happened with President Biden with regard to Afghanistan. War is a tricky thing, especially in the United States where we're raised to expect swift and thorough victory at minimal cost. Johnson's popularity tanked around Vietnam much like Biden's early national grace period came to an abrupt halt in the wake of Afghan loss. So, despite having a decent chance for victory in 1968, Johnson stepped aside with dignity. And the decision appears to have aged fairly well as both he and Harry Truman remain among our most revered presidents despite only running for office once (both are consistently in the C-Span presidential rankings top 10).
At the very least, I hope President Biden doesn't feel obligated or unduly pressured to seek a second term. Because, as demonstrated by some of our best and/or most capable chief executives, there's no dishonor in stepping aside. I would argue, in fact, that there's great dignity in a leader's ability to reject power for the greater good of the nation. We rightly celebrate President Washington even 225 years later for having the grace to step aside after two terms even though he could have very easily won another (likely unopposed) election. Even less celebrated figures like Richard Nixon deserve our applause for sacrificing status and power for the good of the nation.
I believe if President Biden announces (in a year or so) that he doesn't intend to pursue a second term, it won't necessarily be a terrible thing for his legacy, his party, or his nation.