US President Donald Trump(L, front) is greeted by former US President Barack Obama after delivering his inaugural address during the presidential inauguration ceremony at the US. Capitol in Washington D.C., the United States, on Jan. 20, 2017. Donald Trump was sworn in on Friday as the 45th president of the United States. (Xinhua/Yin Bogu)

It's a tradition in the US that ex-presidents don't criticize a successor. It's rare for a predecessor to rebuke an incumbent president. But former president Barack Obama has violated the code of silence, criticizing Donald Trump for mishandling the novel coronavirus epidemic repeatedly. 

After the former president harshly criticized the Trump administration's handling of the coronavirus pandemic as an "absolute chaotic disaster" during a conversation with ex-members of his administration, Obama blamed "folks in charge" for not knowing what they're doing during a virtual commencement address for historically black colleges and universities on Saturday. Responding to Obama's criticism, Trump on Sunday dismissed his predecessor as "grossly incompetent."

What made Obama break the longstanding tradition? The performance of the Trump administration amid the epidemic apparently is too poor to keep the former president silent. With over 1.4 million infections and nearly 90,000 deaths, it's fair to say the US coronavirus response is one of the worst in the world. But where the country is with the virus was not inevitable, but a direct result of Trump administration's failed policies. Although Obama may also want to help Joe Biden, the Democratic candidate, win more support in the presidential campaign, his criticism of the Trump's policy was more out of discontent with the grave epidemic situation in the US. 

The Trump administration in recent days has been hyping up what it is calling "Obamagate" that accuses Obama of attempting to frame Trump for colluding with Russia to win the 2016 election. When the lives of more Americans are under threat from the novel coronavirus, the Trump administration has decided to devote much of their time hyping a conspiracy theory. The purpose is clear: to discredit Biden by attacking Obama and divert people's attention from its failures in dealing with the coronavirus epidemic in order to win reelection. 

Many wonder why the US, the world's only superpower, has failed the international community in the coronavirus fight. That's because when an election is on top of the agenda, politicians will hardly focus on solving real problems the country is facing but take the chance to score more political points. 

Consequently, there will be finger-pointing, war of words and satire - anything but solution to real problems. 

Trump and Biden are accusing each other of being weak on China, despite the fact that the US political elites are increasingly hostile to China. 

With politics increasingly disconnected from reality, the US will only see more problems unsolved and be further mired in a crisis. This is the tragedy of US politics.