Why did John McCain do when he was senetor that made him famous?

John McCain gained prominence as a senator through his bipartisan approach and his willingness to stand up against party lines, particularly on issues like campaign finance reform and Immigration. He became widely recognized for his role in the Senate Armed Services Committee and his advocacy for a strong national defense. His 2008 presidential campaign further elevated his profile, particularly his stance on foreign policy and his criticism of the Obama administration during his later years. Additionally, his dramatic thumbs-down vote against the repeal of the Affordable Care Act in 2017 solidified his legacy as a maverick willing to prioritize principles over party loyalty.