John McCain was a maverick whose last political battle was reining in Donald Trump

During his long years of political service John McCain built - and sought to keep - a reputation as a maverick, who was liable to infuriate his party colleagues almost as much as not.

His votes would more often-than-not toe the Republican party line, but on those occasions where he did not, there would be much gnashing of teeth from the GOP.

Many of those were principled stands, such as in his last two years amid the rise of Donald Trump, but there were also a number of occasions Mr McCain would look back on with regret.

He would gain admirers for his joining with Democrat Ted Kennedy to push a grand compromise over immigration that would pair stronger border protections with a path to citizenship for millions of undocumented migrants. It is the type of compromise Mr Trump would not accept now.

He would also push for campaign finance reform, having nearly had his career ended by a corruption scandal in 1989 where he was faulted by a Senate committee for "poor judgement" - an incident he would say left a permanent mark on his record.

Mr McCain was constantly lauded as an American hero in the wake of his military service and his five years as a prisoner of war in Vietnam . He would often talk about putting country above petty political lines, such as when he supported the release in 2014 of the Senate report on CIA interrogation techniques and torture, which is why he always faced harsh criticism when these morals were seemingly left by the wayside.

In 2000, he moderated his own personal view the Confederate flag should be removed from South Carolina state capital, fearing it would hurt his standing with GOP voters during his first presidential run. In 2010, he was ridiculed over an advert which aimed to deflect attacks that he was soft on the border - undermining years of bipartisan work.

And perhaps most famously, he picked Sarah Palin as his running mate in the 2008 presidential election, which seemingly exposed the arguments within the Republican Party - and it could be argued set the GOP on the road that led to the selection of Donald Trump.

It was against Mr Trump that Mr McCain would make one last political stand. While Mr Trump would expose still further his need to attack and belittle those that speak out against him.

Having criticised Mr McCain for getting captured during the Vietnam War, Mr Trump has also never forgiven Mr McCain for giving a late-night thumbs-down to a years-long effort to repeal Barack Obama's Affordable Care Act, or Obamacare. Mr McCain, rebuffing an 11th-hour appeal from the president, followed through on a threat to oppose the plan if Republicans did not follow “regular order” and allow the legislation to receive a hearing and input from Democrats. Mr McCain has always been one for rules where Mr Trump clearly has not - and it left the president with a grudge.

A similarly rushed-through tax reform bill would have been the perfect platform for another show of bipartisanship, but snapping back to party orthodoxy has he has done numerous time, Mr McCain voted that one through.

However, the Arizona Senator made clear his feelings towards Mr Trump. In a speech last year he condemned "half-baked, spurious nationalism" in a veiled knock at the president's "America First" platform, having also taken issue with Mr Trump's insistence on breaking down almost every norm in foreign relations. He labelled Mr Trump's meeting with Russian President Vladimir Putin in Finland last month: “One of the most disgraceful performances by an American president in memory”.

The fact that Mr Trump did not issue a statement when Mr McCain announced he would be discontinuing his treatment for brain cancer - before issuing a tribute after his death - shows how much the Arizona senator got under the president's skin.

It was the last act of a career that was far from perfect, but certainly earned the moniker 'distinguished'.