All of the Liars

Here is a current list of Trump Campaign-affiliated people who lied (publicly or to FBI) about meetings with Russians over campaign-related topics:

• Paul Manafort
• Carter Page
• Mike Flynn
• Richard Gates
• Jared Kushner
• Jeff Sessions
• Donald Trump Jr.
• George Papadopoulos

Why have so many people affiliated with the Trump Campaign lied about their contacts with Russian officials? 

As the idiom goes, where there's smoke there's fire.