It doesn’t take Trump saying so. Anyone who looks can see the the coordination between the planet’s elite, Clinton campaign, news media and organized crime, in managing the outcome of the election.
What about the polling organizations? There is no reason to think the poling organizations would be left out of the elect Clinton at any cost consortium. What risk are these poling organizations taking with respect to their reputations? The answer is, almost no risk at all. The polls which show Clinton ahead by 7+ points are using their influence to try and swing the election. If the rigging of the election fails, the polls will be moved to favor Trump as the election date nears. The appearance will be that the gap closes naturally.
Some citizens still believe candidates run for office with the intention of serving voters. All parties in an election, do what they do for personal gain. The groups which favor a Clinton presidency are stacking odds of economic success in their favor by using political power,
If the point comes where it appears Clinton will lose, this consortium will break up and there will be a bit of political chaos for a while. Power will not be transferred gently.