Bill Clinton: 'Don't Bet Against John McCain'

Former President Bill Clinton wished Sen. John McCain "a swift recovery" after it was revealed Wednesday night the Arizona Republican has brain cancer.

Clinton joined a chorus of many other current and former politicians expressing well wishes to McCain on Twitter:

As he’s shown his entire life, don’t bet against John McCain. Best wishes to him for a swift recovery.

— Bill Clinton (@billclinton) July 20, 2017

Doctors removed a blood clot from McCain's brain above his left eye last week. CNN reported Wednesday night the 80-year-old also had a brain tumor removed during that procedure.

CNN chief medical correspondent Dr. Sanjay Gupta said the type of cancer McCain has is "very aggressive." He will need additional treatment, either radiation or chemotherapy.

• Sen. Ron Johnson: McCain 'Will Attack' Brain Cancer Diagnosis
• Lindsey Graham: McCain Was 'Forgetful' Before Blood Clot Surgery