It already happened in January 2018.
Trump had demanded $5.7 billion in federal money to pay for his border wall. He shut down the federal government, holding it hostage for 35 days in order to get the funds for the wall.
After prolonged negotiations with Nancy Pelosi and Chuck Shumer, Trump relented and dropped his demands. Those negotiations were described as a political knife fight. Shumer played good cop and Pelosi was the bad cop, going for Trump's jugular vein.
Afterwards, Trump always avoided Nancy Pelosi. Around that same time, GOP propaganda outlets, especially Faux News, began a relentless effort at bad-mouthing Pelosi. Trump was clearly afraid of her.