They are psychologically caught up in an eternal process of "making things better" within the confines of their image of what is best, for everyone, globally. This extends even to those who state that they neither share their beliefs, nor have any interest in the manner in which they propose to fix the so-called problem they have identified.
I am willing to wait, oh, a decade or so, sadly watching Sweden devolve into anarchy, just so I can say, (not in a petty way mind you), "See, we weren't making it all up." to a few friends who would rather wear blinders and buy into a delusion rather than entertain reality.
So don't hesitate to point out failure, even if it takes years. Leftists are generally slow to acknowledge defeat (mind you this is a wing that started rioting upon losing elections as far back as 1968 - something Conservatives would never do), since as ideologues, they have embraced the notion that their beliefs and policies are superior, both morally and practically, and thus, to go against them means you are the one holding the world back from being "perfect".
Well, until they find a way to make jokes illegal.
And that's a very good thing.
Still, you will also need to...
5. Hold to the Philosophic Argument
These principles value Constitutionalism, citizens rights, and picture a government that is subservient and accountable to the people and is diminished in size and power. Neo-Conservatives and Neo-Liberals do not share this goal, and thus, are effectively the enemies (not in a hateful way) of those from the center to the right, and if I may be so bold, they are the enemy of "the people".
So, call them out, and show them that they are working against their own previously held beliefs and are now fighting on the wrong side.
They will also claim, when they don't like the history, that these events occurred, long, long, ago, and so don't matter in the present. Then again, aren't they the ones who want to tear down Confederate statues? Wait, I thought that was a long time ago, and doesn't matter? Oh well, pick and choose, I guess.
Conservatives are Nationalist, make no mistake about it. But they are Civic Nationalists, not Ethnic-Nationalists, as Supremacists are by definition. The Founders didn't give a fig where Americans came from, their race or religion and all that, all long as they shared the philosophy of Civic dedication to the idea of America.
9. Be Conscious of the Left's Unpredictability
10. Let Them Be Themselves
Sadly for the Left, resistance emboldens them, and thus they will invariably "double down", and push ahead with even more radical ideas than before, losing even more centrists, and as we have seen in the last couple of years, as the less radical sector of Liberals who "just weren't Liberal enough" have been alienated from their own party.
11. Celebrate Freedom and Wealth
This can be illustrated no more clearly then by observing a Leftist or Far Leftist Antifa protest, where not one American flag will be seen on display, but instead Cuban, Mexican, Former Soviet, and North Korean flags fly proudly in the air as millennial retro-radicals trod upon the ashes of our nations flag.
One must remember that radical ideologies have little respect for competing philosophies, and this brings them into conflict with the basic Democratic principles of our nation. Notions such as freedom of opinion, speech and discourse, and supporting others wealth, are generally "triggering" to those altruists with other people's money on the Left.
Rabid dogs eventually turn on one another, as we saw DACA recipients turning on their self-appointed protector, Nancy Pelosi, a few weeks ago.
Ironically, 75% of American Jews sadly still vote Democrat, and many of that number self-identify as Socialists, Progressives, or are involved in some way with Social Justice issues. However, this innate Leftist leaning among Jewish-American voters will not spare them from the Progressive backlash, which I expect will alienate more and more Jewish voters over time and push them into the Conservative camp. This arc is being paralleled by a similar percentage of Latinos swinging right, who currently vote 35% Republican, no matter how hard Spanish language media attempts damage control.
While Alt-right racists accept Jews as who they are, and many support Israel (probably as a means to have more Jews leave their "white" nations), Leftists, being good surrogate Afro-Centrists, ascribe to the "illegitimacy theory", which holds that Israel should never have existed and functions as an extension of European imperialism.
Thus, they choose to ignore the multiple centuries of Muslim imperialism in the Holy Land, which was high-lighted by unregulated migration, massacres of Non-Muslims, and forced conversions, and they instead choose to see the Palestinians as yet another among an endless throng of "poor oppressed indigenous peoples" (i.e. non-white) who just couldn't get by without their advocacy for them.
Leftists and other Globalist types often try to conflate issues here, and particularly like to blur their own western racial issues with Israeli intra-cultural issues and draw parallels where none exist, including extending the illegitimacy issue from the right of Israel to exist (i.e. its okay to hate Israel and Zionism - cuz that's not the same as hating Jews...riiggght) to the very nature of Jewish genetics, revealing the Eugenics streak that has not left the Left since Margaret Sanger conceived of Planned Parenthood as a means to limit the number of Blacks and poor whites born into American society.
Regardless of all evidence to the contrary, including a wide range of genetic studies, physical appearance, blood phenotype, etc., etc., leftists are sooner likely to anoint Africans and people of African descent as the heirs to the people they've read about in "their" bible, even though Ashkenazim have been determined to be the inbred descendants of some 600 Judean refugees who escaped from the Third Roman-Jewish War and genocide of second century C.E.
For them to move forward with this falsehood, they must then ascribed to conspiracy theories that endorse alternate folklore, such as Arthur Koestler's thoroughly disproved "Thirteenth Tribe" theory, which posited a mass Turkic conversion to Judaism by a now extinct Crimean tribe known as the Khazars, with no genetic data ever verifying a single Khazar gene.
I mean, maybe it's just me, but what could be more racist than attempting to rob an ethnic group of its cherished identity, or assisting one group to steal another groups identity? Isn't that at the very least the "cultural appropriation" that the Left so frequently goes on about?
On top of that, the real tin-foil hat wearers, when confronted with data that refutes this cock-eyed narrative must then resort to a "worldwide Jewish scientific conspiracy" which must be responsible for falsifying genetic testing the world over.
But, we know of other Socialist political movements in the past that propounded murky international Jewish conspiracies too, don't we?
Currently 89% of African-Americans vote Democrat, and are the end product of a process of Democraticazation that began prior to World War Two and was a fait accompli by the late 1960's. One may wonder why Black voters would sidle up to a party that not only supported slavery but was in essence the Confederacy, but even at the latest date, fought against de-segregation and equal rights, and leading party members such as Senator Robert Byrd, touted open KKK leadership roles. Add to it that LBJ's "Great Society" program in essence created the modern Urban Ghetto as a premeditated facsimile of Reconstruction Sharecropping, and worked counter to the advances the Black middle class had made through the 1930's-1960's, it went on to introduce a series of maladies into the Black community that were much less prominent or were previously non-existent.
"In this deceitful American game of power politics, the Negroes (i.e., the race problem, the integration and civil rights issues) are nothing but tools, used by one group of whites called Liberals against another group of whites called Conservatives, either to get into power or to remain in power. Among whites here in America, the political teams are no longer divided into Democrats and Republicans. The whites who are now struggling for control of the American political throne are divided into "liberal" and "conservative" camps. The white liberals from both parties cross party lines to work together toward the same goal, and white conservatives from both parties do likewise.
The white liberal differs from the white conservative only in one way: the liberal is more deceitful than the conservative. The liberal is more hypocritical than the conservative.
Both want power, but the white liberal is the one who has perfected the art of posing as the Negro's friend and benefactor; and by winning the friendship, allegiance, and support of the Negro, the white liberal is able to use the Negro as a pawn or tool in this political "football game" that is constantly raging between the white liberals and white conservatives.
Politically the American Negro is nothing but a football and the white liberals control this mentally dead ball through tricks of tokenism: false promises of integration and civil rights. In this profitable game of deceiving and exploiting the political politician of the American Negro, those white liberals have the willing cooperation of the Negro civil rights leaders. These "leaders" sell out our people for just a few crumbs of token recognition and token gains. These "leaders" are satisfied with token victories and token progress because they themselves are nothing but token leaders."
Tell that to your Liberal friends.
And lastly, when all else fails...
For example, if an intersectionalist is railing that you can't possibly understand what poor migrants go through, point out your Huguenot or Irish ancestors fleeing from country to country, mention your mentally handicapped niece, what great friends you are with your Muslim tailor, or better yet, if you are a member of one of the "anointed groups" that they give great varying latitude to, such as Blacks, Latinos, Asians, Jews, Muslims, migrants and illegal aliens, LBGT, etc., etc., mention that fact. Though since it is a pecking order, I must warn you that there is the possibility that you may be trumped by a surprise attack. Thus, if you are a Black man, you can be sure that you might get "put in your place" by a Black woman, and she might then be brow-beaten by a Gay Black Handicapped woman, and...well, you get the picture. So be advised.