PHOENIX - Eight years after stumping across the nation as the Republican Party's presidential candidate, Sen. John McCain is back on the campaign trail in his home state as he faces a primary challenge and a strong Democratic opponent in the general election.

Dogging McCain as well is GOP presidential candidate Donald Trump, whose statements in recent weeks have prompted rebukes from the longtime Arizona lawmaker.

McCain lashed out at Trump for attacking the parents of an Army captain killed in Iraq in 2004. Trump drew the ire or many in his party for comments he made attacking Khizr and Ghazala Khan, who spoke at the Democratic National Convention.

McCain also slammed Trump for saying he might not come to the aid of NATO countries that failed to fulfill their financial obligations.

Yet McCain has stuck by his support for Trump and reiterated it to reporters this week.