In a letter posted on his website today, Icahn announced he is committing $150 million of his own money to a yet-unnamed new Super PAC, which will also raise funds from third parties. The primary focus of the Super PAC, he says, will be to push Congress to stop U.S. corporations from moving overseas for tax purposes, a process that's become known as "corporate tax inversions." For Icahn, that trend is among the biggest threats to the country's economy.

"If this exodus is allowed to accelerate, there will be disastrous consequences for our already fragile economy, as well as meaningful and unnecessary job losses," Icahn writes.

While Icahn has focused on the tech industry in recent years, as the 2016 election season heats up, he's made no secret of his political interests.