Jay Parini, a poet and novelist, teaches at Middlebury College in Vermont. His latest book is " New and Collected Poems, 1975-2015 ." The opinions expressed in this commentary are solely those of the author.

(CNN) The contrast could not be more extreme: a loud, pushy, anti-intellectual President Donald Trump versus a soft-spoken, recessive, philosophical former president, Barack Obama. The difference has become especially glaring in recent days, with Trump repeatedly breaking the tradition of a new president refraining from dissing his predecessor.

Trump has, in fact, gone out of his way to attack Obama, as in his recent nonsensical reversal wherein he attacked Obama for his lack of response to Russian meddling in the 2016 election: "Obama did NOTHING," Trump tweeted. He went on to accuse Obama of colluding with the Russians!

By now the world is familiar with this Trump ploy: He engages in unscrupulous business deals , so he labels Hillary Clinton "Crooked Hillary." He lies, so he calls Ted Cruz "Lyin' Ted." On and on. Anyone who calls him out on any failure gets the same accusation hurled back in his or her face, and -- to a shocking extent -- this trick works. Or it works with Trump supporters, who don't seem to care if he wrecks their health care, allows factories to poison their water, or provides massive tax cuts for the rich people they admire so much. THIS is making America great again.

The truth is, Obama confronted Putin directly about intervening in our political system and put in place sanctions, though he clearly didn't do enough. "I feel like we sort of choked," one former colleague of Obama has said, according to an article in the Washington Post . This is too bad, as the Russians pulled off the crime of the century, possibly derailing Clinton, a tough critic of Russia. Today we have an incompetent President who (for reasons we might discover soon enough) appears unwilling to oppose the Russian regime.

Obama's weak responses to Trump have been troubling. I don't know why he didn't simply open the intelligence files on Putin to the American public, saying: "My God, look what the Russians are trying to do! Put up your guard!" There can be no sound reason for not alerting the people of this country to a major attack on their most cherished right, the right to vote.

I'm also unhappy about Obama's response to Trumpcare. His language was strong enough:

JUST WATCHED Trump tries to shift hacking focus to Obama Replay More Videos ... MUST WATCH Trump tries to shift hacking focus to Obama 04:48

"The Senate bill, unveiled today, is not a health care bill," he wrote in a Facebook post, blasting the Republican legislation that seeks to repeal and replace the Affordable Care Act. He calls the proposed Republican plan "a massive transfer of wealth from middle-class and poor families to the richest people in America." That is exactly what he should have said, but why is he only saying it in a Facebook post rather than in remarks to the press or in speeches.

Again and again, Trump strikes and Obama turns the other cheek. What's going on here?

There is a longstanding Christian tradition of turning the other cheek, and that's usually the best approach to abuse. But one should remember that Jesus also turned over the tables of merchants and moneychangers in Herod's Temple in Jerusalem. He accused them of transforming the holiest site in Judaism into a "den of thieves." (Mark 11:17) I wonder if the analogy here, with Trump and his cohorts, isn't more apt than we think.

A friend of mine recently suggested that Obama was, at heart, a quietist. This is a mystical tradition that involves a "quieting" of the conscious mind, a withdrawal into the deepest layers of self, even self-annihilation. Political quietism involves stepping back from the activities of the world to focus on religious truth, and it condemns self-aggrandizement and the naked reach for power. It rejects the quest for wealth.

JUST WATCHED Trump to Obama in 2013: Do not attack Syria Replay More Videos ... MUST WATCH Trump to Obama in 2013: Do not attack Syria 00:45

But quietism seems misguided in this context. Political life is where we create a community. What is government but our community made visible? If we are to create a community that takes pride in how it cares for its own, one that promotes decent values, such as humility and tolerance and the wish to share, we have no choice but to step forward, to declare ourselves and speak up for our values.

Obama needs to find his voice now in ways that, during his time in the Oval Office, he was too often reluctant to do, perhaps fearing the immense power of the bully pulpit

But now there is a real bully in the pulpit, and Obama -- like the rest of us -- has no choice but to speak, and to act.

My hope for Obama is that, in his post-presidency, he steps forward boldly to say whatever feels true in his mind. And he must do so in the most public ways. I would urge him to speak up, not indirectly on Facebook, but to declare himself more publicly and without reservation, revealing his ideas, his passions. There may be some fatal flaw here, of course, one that disallows a full-throated singing of his song. But I hope it isn't so.