The journalist and former Trump loyalist tweeted that losing the election "revealed a dysfunction I had refused to see."
Rivera also urged Trump to stop giving his supporters "false sense" of hope about overturning the election result.
On Fox News, Rivera responded forcefully to Limbaugh's comments that political division could lead to a Civil War-style break-up of the U.S.
"Well done President Trump. Congratulations General Flynn and family. Happy Thanksgiving," Rivera wrote on Twitter on Wednesday.
"This is silly stuff," the Fox News correspondent said, calling Giuliani's and Powell's press conference a "circus."
CNN's Don Lemon said it "might make this snowflake of a president feel better."
As "Trump Vaccine" trended on Twitter, one user said: "I thought electing Biden was the Trump Vaccine."
Network's contributor told "Fox and Friends" that Trump could "become kind of a generic name" for the vaccine.
The Fox News personality thinks the president should be more humble in how he talks about beating COVID-19.
Fox hosts Geraldo Rivera and Brian Kilmeade debated whether Trump's Iran drone strike was necessary on Friday morning.
Trump could win 40 percent of the Latino vote in 2020 and if he courts DACA recipients, Rivera said.
"I'm not a shill for Twitter, I enjoy the fact the president is on Twitter and he follows me," Rivera said.
Fox News host Sean Hannity said he knows "some great divorced dads" during his show after former First Lady Michelle Obama made what he called "demeaning" comments.
"I see [impeachment] as a distinct possibility," Fox News commentator Geraldo Rivera said Friday morning.
On Sunday, U.S. Customs and Border Protection said it had deployed tear gas after "several migrants threw projectiles."
The Fox News contributor apologized to Midler but also said he remembered things differently