If we could bet on politics an extremely safe one would be betting that incumbent Senators would win re-election. According to OpenSecrets, since 1964 the average re-election rate for the Senate has been higher than 82%. That's a safe bet.
Why? Incumbents have a massive advantage in fundraising over their challengers. The analysis below shows that in 2018, outside of a few high profile races, the incumbent had raised substantially more than their challenger. However, there is hope in that in 3 of the 5 biggest races (Florida, Indiana, and Nevada) the challenger had raised more than the incumbent and won the seat. Of particular interest was Arizona where the seat was open and the amount of funds raised were approximately equal between the two parties.
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