For what it's worth, the Missouri senate race is tied, 45-45%, in an average of polling conducted so far this year.
Remington Research, 4/19-20: McCaskill 48-44%
Mason Dixon, 4/4-6: McCaskill 45-44%
Gravis Marketing, 3/5-7: McCaskill 42-40%
Axios/Survey Monkey, 2/12-3/5: Hawley 52-44%
PPP, 1/8-9: McCaskill 45-44%
McCaskill is clearly leading if you exclude the Survey Monkey poll, which absolutely should be excluded due to the completely unscientific nature of how Survey Monkey polls work.
With survey monkey, anyone can create a poll, and then they can send it out to others however they want, and taking it is completely voluntary.
So this is actually completely possible with Survey Monkey:
1. Get a campaign staffer to create a poll for their race.
2. Send the poll out to the entire mailing list of the politician in question.
3. Watch as the skewed sample creates a skewed result.
Survey Monkey was designed for businesses to poll their customers to gauge what their customers want to see (who will only take the time to fill it out if they have strong preferences, and in a way that can easily be set up to reach their target audience, and their target audience only); not for political organizations to poll political topics.