(CNN) Prosecutors closed their criminal trial of Republican politico Roger Stone on Wednesday by making a forceful argument that the longtime Washington operator had lied to Congress about his engagement with WikiLeaks in 2016 to shield one person: President Donald Trump.

Prosecutor Jonathan Kravis, who delivered a closing argument for the prosecution, told the jury that if the truth about Stone's activities on Trump's behalf had come out in 2016, "it would look terrible." Emails and texts showed, Kravis said, that Stone sought to learn about documents that WikiLeaks had that could help Trump and spoke to the Trump campaign about it.

And, Kravis added, if Stone had told Congress the truth about his campaign pursuits, "It would look really bad for his longtime associate Donald Trump."

Closing arguments in Stone's case provided an opportunity for prosecutors from the DC US Attorney's Office to remind the jury of evidence they said proved that Stone had lied to Congress in September 2017. But the arguments also allowed a team that had worked with Robert Mueller's special counsel investigation into Russian interference in the 2016 US presidential election to rehash the Trump campaign's interest in WikiLeaks in 2016 and the damage the alleged lies had done in subsequent investigations.

Stone, a political provocateur and longtime Trump ally, is on trial in Washington for charges that include lying to Congress, witness tampering and obstructing a congressional proceeding. Prosecutors allege he failed to turn over documents to Congress in 2017 that showed he had sought to reach WikiLeaks the previous year, and say he lied about five facts, obscuring his attempt to use a back channel to get information that could help then-candidate Trump. Stone has pleaded not guilty to the seven charges.

Read More