Michael Bloomberg’s big-spending, shock-and-awe TV ad campaign has made politicking more expensive for everyone from his 2020 rivals to Senate, House and state legislative candidates around the country.

Eight weeks into his presidential campaign, Bloomberg has already spent more money on advertising — $248 million — than most candidates could spend in years. That amount has squeezed TV ad inventory in nearly every state, lowering supply and causing stations to raise ad prices at a time of high demand, as candidates around the country gear up for their primaries.

On average in markets around the country, prices for political TV ads have risen by 20 percent since Bloomberg began his campaign. Meanwhile, some local politicians have already found difficulty trying to reach their own constituencies.

“I think we might have been one of the first campaigns to experience the ‘Bloomberg Effect’ on prices, but we certainly won't be the last,” said Eric Jaye, a California-based media buyer who purchased ads for Sylvester Turner, the just-reelected Democratic mayor of Houston.