Liberal creep is liberal bias that gradually creeps or distorts an entry, definition, explanation, description, or historical account.
Former Utah state Sen. Bill Wright may have been the first to coin this term in spring 2008 when he "warned of liberal creep — the 'education of indoctrination' — in which the media peddle "socialism and programs. We have been so dumbed-down, so indoctrinated with all this information we’re in a haze; we can’t see through it. We must find out for ourselves."
Examples of liberal creep include:
- Ronald Reagan left the White House with the best approval ratings of any president, up to that time, at the end of his term, yet the media and history books have since relentlessly tried to downplay and distort his political achievements.
- Reverse to the above example, Bill Clinton  left office after a failed impeachment attempt on perjury charges, yet liberal creep ensures that this is downplayed and distorted.
- Many early scientists such as Isaac Newton and Galileo Galilei were heavily influenced by Christianity and would never have made their important discoveries without their faith in the Lord Almighty, yet that faith has since been downplayed in liberal atheistic public school textbooks and Wikipedia. 
- The ferocity and savageness of the Native Americans towards American settlers has gradually been downplayed, while the relocation of the Cherokee has been gradually inflated to the point that some liberal textbooks treat it as an atrocity comparable to the Holocaust. Similarly, there has been an increase in denial of the many technological and spiritual improvements the settlers brought to previous inhabitants.
- Clinton left office with a higher approval rating than Reagan. 
- For example, the Wikipedia entry on Isaac Newton completely omits how he was a devout Christian who read the Bible daily and derived his inspiration and motivation from it.
- Wikipedia has a comprehensive article detailing Newton's religious views that utilizes similar content and references.