Sens. John McCain and Lindsey Graham are not likely to pull punches when they discuss cyberthreats to the United States Thursday. | Getty

John McCain and Lindsey Graham have spent the past eight years chiding President Barack Obama’s foreign policy, sarcastically calling the president naïve when it comes to world affairs and regularly grilling his Cabinet members at congressional hearings.

Now, it’s Donald Trump’s turn to be the target.

McCain and Graham, the maverick partners on an array of issues, will take the stage Thursday on the matter of cyberthreats to the United States broadly, and Russian interference in the U.S. election specifically. And, true to form, neither is likely to pull punches — never mind that a member of their own party who has repeatedly downplayed the notion that Russian meddling might have aided his campaign is about to be sworn in as president.

“You can expect I’ll do what I’ve been doing: I worked with Obama, though I didn’t agree with him, I certainly was a check,” Graham said in an interview. “I have a lot in common with President-elect Trump in terms of the domestic agenda. When it comes to foreign policy, I agree with him on Iran, I agree with him on China. Russia: I have no idea where he’s coming from.”

The Thursday hearing before the Senate Armed Services Committee is the first of what McCain says will be an extensive effort to investigate the cyberthreats that the longtime U.S. adversary and other hostile nations pose to the United States.

A source familiar with Thursday’s hearing said that while the panel has a cybersecurity focus, the assumption is that senators will zero in on Russian intrusion in the election. McCain is calling several of the top U.S. voices on intelligence to testify, including Director of National Intelligence James Clapper and National Security Agency chief Adm. Mike Rogers. It will be a public forum, before potentially moving to a closed-door classified meeting later in the day.

Their investigation, which includes a new panel on cybersecurity headed by Graham, could end up being the only effort in a GOP-controlled Congress that directly clashes with Trump and his skepticism of the U.S. intelligence community. Despite a growing consensus in the intelligence world that Russia actively tried to tilt the election toward Trump, the president-elect has repeatedly expressed doubt. This week, he referred to the “so-called Russian hacking.”