As the Russia investigation intensifies, President Trump has fluctuated his stance on the FBI's credibility and independence. (Joyce Koh/The Washington Post)

Throughout the 2016 campaign, Donald Trump positioned himself as a great defender of law enforcement — particularly against those critical of the community.

In the moments after he became president, Trump promised in his inaugural address that the nation would always be safe.

“There should be no fear: We are protected, and we will always be protected. . . . We will be protected by the great men and women of our military and law enforcement and, most importantly, we are protected by God.”

And as recently as December, he tweeted “God bless you all” to law enforcement.

As the nation's premier law enforcement agency, the FBI was included in Trump's circle of praise. He regularly sent out tweets praising the agency and applauding it for its service, particularly after shootings or terrorist attacks. He praised the FBI for its response to the Boston Marathon bombing or used a retired agent's comments to back his claims of American Muslims celebrating on 9/11. 

He took special delight when the agency was investigating his Democratic rival, Hillary Clinton, for the use of a private email server while she served as secretary of state.

Republican presidential candidate Donald Trump opened a rally in Manchester, N.H., Oct. 28, discussing news about the FBI investigation into Hillary Clinton's time as secretary of state. (The Washington Post)

But since the election, Trump's tone has changed when it comes to the FBI. As the agency's investigation into Russian interference in the election has  increasingly focused on possible interaction with his campaign, his rhetoric has seemingly moved from rebuttal to retribution.

In discussing the investigation Wednesday with reporters, Trump said he was merely “fight[ing] back.” He has spent much of the past year fighting back against the investigation and the FBI for issues related to the investigation.

Trump tweeted that the federal law enforcement agency was “once cherished and great.” He's regularly accused the FBI of leaks. And he called an agent on the Clinton probe “tainted” and “dishonest.” 

“Now it all starts to make sense,” the president suggested in another tweet, seeming to imply a conspiracy against him.

And not to mention all the times he has suggested that the FBI's real focus should still be on Clinton.

It all follows a similar trend of the Trump presidency: If the system is against him, it must be corrupt, and that includes federal law enforcement. He's even implied the FBI and Justice Department are part of a “Deep State.”

After it became public that the FBI failed to save text messages from former Mueller team members who were critical of Trump, the president suggested that the FBI was not trustworthy. (The messages were later recovered, the Department of Justice inspector general announced Thursday.)

During the campaign, Trump's frequent praise of law enforcement at rallies and on social media appeared to be a rejection of the growing criticism of police officers heading into the 2016 election as brutality and the shootings of unarmed black men became a growing concern among Americans, which sometimes led Trump to criticize the activists.

And when the Obama White House moved to create the 21st Century Policing task force to “strengthen trust among law enforcement officers and the communities they serve,” Trump suggested that his predecessor didn't respect law enforcement.

Now, Trump's criticism of federal law enforcement has some believing that he may actually be the one who doesn't respect those charged with protecting Americans.

Trump often uses Twitter to draw attention to institutions he believes shouldn't be trusted, including the news media and the Democratic Party. As he continuously claims “no collusion” while attacking the FBI, it seems the president's ultimate goal has been to discredit the Russia investigation -- a preemptive strike to any possible revelations of ties disclosed between the Kremlin and his campaign.

But the president's growing criticism of law enforcement after years of praise is causing some Americans — especially among his base — to have less support in some members of law enforcement. While slightly less than a third — 31 percent — of adults disapprove of the way special counsel Robert S. Mueller III is handling the investigation, nearly half — 49 percent — of Republicans disapprove.

In “fight[ing] back,” Trump seems to show less confidence in certain law enforcement officials and appears to want his supporters to do the same. But that may come at a cost to the FBI and law enforcement in general.