MILWAUKEE (AP) — Wisonsin Governor Scott Walker is calling on those who backed his ill-fated presidential run to now vote for Texas Sen. Ted Cruz, saying a win for him Tuesday will change momentum in the race.

(Photo by Justin Sullivan/Getty Images)

Walker introduced his former rival at a Republican Party event in Milwaukee on Friday in their first joint appearance since the two-term governor endorsed Cruz on Monday.

Ohio Governor John Kasich and former Alaska Governor Sarah Palin, appearing on behalf of Donald Trump, also spoke at the event that attracted about 750 party activists.

It comes just four days before the Wisconsin primary, where 42 delegates are at stake. A Marquette University Law School poll released Wednesday showed Cruz leading with 40 percent, followed by Trump at 30 percent and Kasich at 21 percent.