In an interview on "America's Newsroom," Friday, Spicer said Democrats were hoping to garner support to move forward with impeachment proceedings -- but Wednesday's hearings did not yield the results they were hoping for.
"That hearing really took the wind out of their sails. This was supposed to be the visual manifestation of the report. They thought the American people would be with them after Mueller testified," said Spicer.
Mueller, who spoke before two House panels earlier this week seemed unfamiliar with his report, appearing confused and frazzled at points throughout the questioning.
Following the proceedings, many Republican lawmakers said they are ready to "close the case" on the two-year investigation, while House Democrats hope to continue into the fall.
When asked why he felt Democrats refuse to put the investigation to rest, Spicer said it boiled down to "keeping their base motivated," and the fact that "the president is getting things done."
"The president is actually getting things done, they can't run against the economy, against all the other things that the president is doing because by-and-large the American people support the President's policies and the accomplishments that he's receiving," he said.
Commenting on a statement by House Speaker Nancy Pelosi where she asked what information Russian President Vladimir Putin had "politically, financially, or personally" on Trump, Spicer said the comments were "tiring" and he believes House Democrats have locked themselves into a corner by putting "all their eggs in one basket."
"They are starting to recognize that the American people said, we gave these people the majority and look at what they've done. They're not fighting for these progressive policies. They're not keeping their base happy on the policy front...and the American people are wondering whether or not they are proper stewards of this majority."