Once Mr. Trump entered the Oval Office, Mr. McCain generally supported the administration’s policies and nominees, including a $1.5 trillion tax cut and the confirmation of Justice Neil M. Gorsuch to the Supreme Court. But in key moments, the senator remained a forceful adversary, and neither man yielded as Mr. McCain battled terminal illness.
Mr. McCain thwarted a Republican effort to repeal the Affordable Care Act last year, returning to the Senate floor after his brain cancer diagnosis to cast a dramatic thumbs-down vote. More recently, Mr. McCain issued a statement critical of Mr. Trump’s summit meeting in Helsinki, Finland, with President Vladimir V. Putin of Russia calling it “one of the most disgraceful performances by an American president in memory.”
This month, as Mr. McCain was ailing, President Trump gave a 28-minute speech about a bill named for Mr. McCain — but did not mention the senator at all.
Elsewhere, Mr. McCain’s long military and political history — and his willingness to at times defy the Republican agenda — won him praise from both parties at the end of his life.
President Barack Obama, who defeated Mr. McCain in the 2008 presidential election, said in a statement on Saturday night that “we shared, for all our differences, a fidelity to something higher — the ideals for which generations of Americans and immigrants alike have fought, marched and sacrificed.”
Mr. Obama also alluded to Mr. McCain’s military service, saying: “All of us can aspire to the courage to put the greater good above our own. At John’s best, he showed us what that means. And for that, we are all in his debt.”
Including Mr. Obama, every living former president released statements commemorating Mr. McCain. President George W. Bush, who won the Republican nomination for president over Mr. McCain in 2000, said in his statement: “Some lives are so vivid, it is difficult to imagine them ended. Some voices are so vibrant it is hard to imagine them stilled.”