Editor’s Note: Frida Ghitis, a former CNN producer and correspondent, is a world affairs columnist. She is a frequent opinion contributor to CNN, a contributing columnist to the Washington Post and a columnist for World Politics Review. Follow her on Twitter @fridaghitis. The opinions expressed in this commentary are those of the author. Read more opinion on CNN.

CNN  — 

President Donald Trump is betting that Americans will become so accustomed to his transgressions that they will become immune to outrage; that they will inoculate him against impeachment.

That may be why on Thursday he made a calculated tactical move. He confessed to asking Ukraine to investigate Joe Biden, and his son Hunter Biden, and he publicly doubled down, urging yet another foreign government to interfere in US democracy. He suggested that China should investigate Biden, one of his leading opponents in the 2020 presidential election. (There is no evidence of wrongdoing by Joe or Hunter Biden in Ukraine. There’s also no evidence that the former vice president received any money from China.)