by Matthew Rusling

WASHINGTON, May 21 (Xinhua) -- U.S. President Donald Trump is lashing out at the Federal Bureau of Investigation (FBI) over the Russia probe, a move that experts said is a bid to change the narrative and claim the investigation against him is purely political.

Trump demanded in a tweet that the Justice Department investigate whether they or the FBI surveilled his campaign at the behest of the Obama administration in the lead up to the 2016 presidential elections.

"I hereby demand, and will do so officially tomorrow, that the Department of Justice look into whether or not the FBI/DOJ infiltrated or surveilled the Trump Campaign for Political Purposes - and if any such demands or requests were made by people within the Obama Administration!" the president tweeted Sunday.

The statement comes amid an ongoing probe by special counsel Robert Mueller on whether Team Trump colluded with Russia to clinch the White House in the 2016 presidential elections.

Last week marked the one-year anniversary into the investigation. While the White House continues to dismiss these claims, the investigation is not going away, experts said.

"I believe Trump's goal here is to try to create an impression that the various investigations into his administration are motivated by politics, not a genuine pursuit of wrongdoing. That's aimed largely at his supporters, not just in the run-up to the midterms but more generally. These charges turn the discussion from 'Is Trump guilty?' to 'Is the investigation political?' which probably benefits Trump in the short term," Christopher Galdieri, assistant professor at Saint Anselm College, told Xinhua.

"He's creating an impression that federal law enforcement is motivated by political concerns, not the pursuit of justice. He's also potentially laying the groundwork for himself to use the FBI and DOJ for political ends - if he convinces his supporters that that's just what presidents do, then they, at least, would support any efforts on his part to do the same," Galdieri said.

"And thanks to political polarization, there are millions of Americans who support Trump and are now convinced that the FBI and DOJ are not professional law enforcement agencies, but left-wing cabals trying to bring down Trump and his administration," Galdieri said.

Brookings Institution Senior Fellow Darrell West told Xinhua: "When Trump is under duress, he loves to change the topic. He is demanding that the Justice Department investigate possible spying on his campaign as a way to argue the entire investigation against him is tainted and unfair. If people believe the FBI spied on him, that discredits investigators and casts doubt on their entire enterprise. It is a way to play offense instead of defense."

Dan Mahaffee, senior vice president and director of policy at the Center for the Study of Congress and the Presidency, told Xinhua that Trump made this demand to highlight what he sees as unfair treatment of his campaign by the FBI investigation.

"Even though it is worth noting that the FBI did nothing publicly related to Trump in 2016 as it did with the Clinton e-mail investigation," he said, noting Democratic nominee Hillary Clinton's email scandal.

"This is a powerful motivating factor for his base, who believe in some kind of 'deep state' conspiracy" to undermine the Trump administration and see the Mueller investigation as a key part of it," Mahaffee said.

"The rule of law in the United States has always been based on the idea that the Department of Justice and federal law enforcement are firewalled from politics. The same is true of the protection of intelligence sources and methods. That is no longer the case, and it sends a powerful message to not only the dedicated leadership of law enforcement and intelligence agencies, but also to criminals and adversaries of the United States," Mahaffee said.