Republican U.S. Sen. Ron Johnson hasn't announced if he's running next year but he's still raising campaign cash

Republican U.S. Sen. Ron Johnson is still asking supporters for campaign cash even as he keeps the political world on hold about his plans on whether to run for a third term next year.

In a fundraising letter dated May 25, Johnson ripped President Joe Biden for "preparing an enormous tax increase."

Johnson said he was "reaching out to fellow Wisconsin conservatives who share my belief in free enterprise, limited government, and our constitutional liberties ... before it's too late."

And he also asked for a contribution of up to $2,900 to "Ron Johnson for Senate," so that "we have the financial firepower to speak truth to power and make sure our nation-saving viewpoint and our prudent, conservative principles prevail."

Just because he's raising cash doesn't necessarily mean he's going to run again.

But Johnson is clearly keeping his options open as a large Democratic field of candidates assembles to take him on.

During the first three months of the year, Johnson raised $545,000 according to federal filings. As of March 31, the campaign had a little more than $1 million cash on hand.

His numbers were below what he recorded six years at the same stage of the campaign. In the first three months of 2015, he raised around $1.3 million and had $1.5 million cash on hand.

Comparing fundraising through the two cycles, Johnson raised about $5 million from January, 2011 through March of 2015, compared to $2.2 million from January, 2017 through March of this year.

Overall, Johnson raised $17.6 million in the 2016 race in which he defeated Democrat Russ Feingold in a rematch.

Democrat Alex Lasry, on leave from his executive job with the Milwaukee Bucks, led first-quarter fundraising with $1,086,812 in contributions.

Johnson is scheduled to take questions Thursday in a virtual meeting with the Milwaukee Press Club.

Journal Sentinel reporter Cary Spivak contributed to this report.