By Government of Thailand (Hillary Clinton เข้าพบนายกรัฐมนตรี) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
The Hillary Clinton Campaign and Democratic National Committee (DNC) paid Christopher Steele $160,000 to circulate a dossier alleging connections with the Kremlin, as well as salacious details about the President's sexual proclivities. This started the rumblings about connections with Russia. After the President fired FBI Director James Comey and charges of a cover-up were leveled, Robert Mueller was appointed as a special counsel to determine the extent of Russian involvement in the 2016 election, and if the Trump campaign was involved.
Since then, continuous leaks to the media have tracked the "progress'" of the investigation and indicated that no evidence of Trump ties to Russia exists. Observers of the investigation notice that Mueller is focusing on process crimes rather than actual connections with Russia; this means that Mueller's investigation has exceeded its mandate, and is more interested in bringing down the administration than answering questions. The investigation has turned into a partisan weapon by Trump's opposition and has formed the basis of many outrageous attacks launched against the President.