MSNBC's Rachel Maddow takes down Donald Trump's war on agent Peter Strzok with shocking tale of his work at the FBI

FBI agent Peter Strzok is scheduled to testify before Congress Thursday morning, so MSNBC's Rachel Maddow spent Wednesday's opener revealing the agent's history and successes stopping Russian spies in the United States.

It all began with the "Boston Conspirators," a couple that were sent to the United States by Moscow to spy on America.

Donald Heathfield and Tracey Lee Ann Foley worked to garner information from policymakers, elected officials, a high-ranking United States Government national security official as well as a U.S. official working on nuclear weapons at a U.S. research facility. The FBI watched them for years as they did the work of the Russian government. The FBI gathered information from the couple without them even knowing about it. They learned ways in which Russia was embedding information in digital graphics and smuggling information out of the United States.

"Counter intelligence division at the FBI pulled the plug on these Russian illegals, including Donald Heathfield and Tracy Lee Anne Foley in 2010," Maddow continued. "Under that indictment that was unsealed in 2010, all in one day, all across the country, they and all the other illegals were all arrested and sent home in a big highly publicized spy swap."

This didn't all happen during the Cold War, the FBI watched them for a decade, but the trial was ultimately held in 2010. Their story became the basis for the television show "The Americans."

The lead agent at the FBI who worked on the espionage cases was Peter Strzok. The same Peter Strzok who became the lead on the Hillary Clinton email scandal and the then-unexplained Russian involvement in President Donald Trump's election. The same Peter Strzok that the president has started a personal war with. So, when the president rails against Congress and Strzok for not doing a public hearing before giving a classified one to Congress, his background as a lead agent of counter-intelligence at the FBI is probably the reason.

"He actually won a medal for that one," Maddow said of Strzok's work on the case from 2010.

The host then noted that Trump loves to blast Strzok for being anti-Trump in his "damning text messages" to his girlfriend Lisa Page, but he hasn't tweeted out some of the text messages that talk about Russian interference in the 2016 election.

"F*ck the cheating motherf*cking Russians," he texted in late July. "Bastards. I hate them. I think they're the worst. F*cking conniving, cheating savages. At statecraft, athletics, you name it. I'm glad I'm on Team USA."

She noted that the GOP has "seized" on Strzok thinking that he will become their way to make the Russia investigation go away.

"A couple of problems with that strategy, which we are going to see in living color over the next 24 hours, including starting tomorrow morning," Maddow said. "One problem they've got is what his actual job was at the FBI. He ran counter-intelligence in this country at the FBI. Destroying him says something about congressional Republicans' view of the value of counter-intelligence at the time when there is an active concern about that for a lot of Americans for a lot of obvious reasons."

She explained that she didn't anticipate it stopping them, but it certainly posed a problem for the United States intelligence and security.

Another problem for the GOP is that Strzok is "not the world's greatest doormat," she said of the FBI agent fighting back. His attorney has released statements saying that the text messages that are anti-Trump were not about bias but about the information available to him.

Strzok public testimony begins Thursday morning.

Watch Maddow's full take on the FBI agent and his work below:

Part 1:

Part 2:

Part 3: