NEW YORK (AP) — New York billionaire Michael Bloomberg, who is deciding whether to launch a Democratic presidential bid, is pouring $100 million into an online advertising campaign attacking President Donald Trump.

The campaign, which targets voters in four general election battleground states — Arizona, Michigan, Pennsylvania and Wisconsin — begins running on Friday, according to Bloomberg spokesman Jason Schechter.

News of the massive investment was first reported by The New York Times. The former New York City mayor has already filed paperwork in at least two states to appear on presidential primary ballots.

Bloomberg himself is not featured in the ad campaign.

One example of a new ad: An image of Trump’s Twitter account that says, “A TWEET SHOULDN’T THREATEN OUR COUNTRY’S SECURITY.”