> For example, centrists during slave-owning times called for better treatment of slaves or at the very least providing compensation to owners of freed slaves.

A centrist lincoln may have been able to avoid a civil war and still free slaves or if war is unavoidable, the south will look like unreasonable extremists rebelling against such a moderate leader and have less support. You make it sound like compensating slave owners was a bad thing, if it avoided the civil war by all means, what a tiny price to pay, even today's divisions wouldn't exist thanks to that.

I like centrist presidents because they have the power to start wars, fire nukes, divide a nation badly (see trump),etc... most people these days (both sides of politics) are deeply and disturbingly ungrateful for the prosperity they enjoy and and the peace and amazing tranquility they've had for many decades now. Frankly, that will be the reason (just like how 1860's americans forgot the 1779-1812 war era and became ungrateful for peace) why a second civil war is unavoidable. They say people forget the lessons of war once the war generation fades away (~50 years). If you keep dividing the country over your change, the price will be blood and loss of prosperity.

You are missing my point though, centrism is not an ideology but like liberalism and conservatism you shouldn't worship it like a religion. For each topic you should figure out what is correct not what aligns with your ideology.

But a person that tends to think moderation, balance, unity and peace are more important than change and solving problems might be described as a centrist but you can believe that and still believe the only way to liberate slaves is through war. I would expect the house of reps to support and insist on war first though since they are the most attuned to the people and overcome resistance from the senate who will delay things enough for hot heads to cool and the president's veto powers so that a super majority is needed if millions of citizens are going to die.

Being right doesn't make all the blood and misery any more appealing. Centrists as things stand today force extremists to compromise leading to less division. Extremists will burn down their house to prove their views about fire response is true, centrists delay them long enough for the firetrucks to arrive. Knowledge and passion lead to extremism, wisdom leads to moderate centrism.

I don't know if biden is a centrist or not, I think he's quite liberal and extreme in some cases. He just happens to be compromising on passionate issues so that he can get things that people actually care about done, not because he disagrees with extreme progressives but because he sees the needs of the whole country not just new york and california and even with them included people care about jobs and economy first and foremost which is what he focused on. The thing about extremists is that they tend to not represent the whole country. A lot of the extreme changes they want need to be done at the state level or by congress not with the president's support. Congress should have some unity or consensus before expecting the president to throw in his weight. President's are supposed to execute and get things done, they shouldn't legislate.