The world’s No. 1 golfer issued a challenge of presidential proportions on Tuesday — calling on George W. Bush to take the icy plunge in the fight against Lou Gehrig’s disease.

Rory McIlroy joined former top-ranked Tiger Woods in an ice-bucket dumping on Tuesday, and he named President Bush and a couple of others as those he'd like to see take an ice bath for ALS charity.

McIlroy and Woods' participation highlights the broad reach of the viral social media campaign, which has swept through the ranks of Hollywood actors, corporate CEOs and professional athletes, but hasn’t reached too far into political circles.

Nominated many times over, President Obama said last week that he would make a donation rather than take the ice dunking.

As of Tuesday, the ALS Association has received $22.9 million in donations, compared with $1.9 million during the same three-week period last year. The donations have come from existing donors and 453,210 new people.

McIlroy, a 25-year-old golfer from Northern Ireland who now lives in Florida, has won his last three tournaments, including two majors — the British Open and PGA Championship — this summer.

Woods nominated Phil Knight and Rafael Nadal, while McIlroy nominated Bush, Wayne Rooney and actor Meghan Markle.