Wisconsin Gov. Scott Walker tipped his hat to Texas Sen. Ted Cruz in the Republican presidential primary. His state is the next to vote, holding its primary on April 5th.
"I just fundamentally believe that he's a constitutional conservative," he told conservative radio host Charles Sykes on WTMJ radio in Milwaukee.
Walker was once one of the Republican presidential candidates considered a favorite to win the party's nomination. But after just a few short weeks in the race, the governor in September abruptly dropped out amid financial woes.
On Monday night, Cruz expressed his hope that Walker would back his candidacy.
"Of course I would welcome Scott Walker's support, anyone would," Cruz told reporters on Monday evening before a campaign stop in Rothschild, Wisconsin. "Scott Walker's support would be tremendously important."
Walker told Sykes that "Ted Cruz is the best positioned by far" to win the Republican nomination and then the general election.
"I'm all in," Walker said. "This is not a default candidate."
But last week, Walker turned heads when he suggested an open convention would lead to a nominee not that is not Trump, Cruz or Kasich.
"I think if it's an open convention, it's very likely it would be someone who's not currently running," said Walker, according to Madison's The Capital Times.
Trump, seemingly preempting Walker's announcement, tweeted on Monday night: "After the way I beat Gov. Scott Walker (and Jeb, Rand, Marco and all others) in the Presidential Primaries, no way he would ever endorse me!"
At a press conference announcing the suspension of his campaign in September, Walker indirectly took a swipe at Trump, saying at the time: "I would encourage other Republican presidential candidates to [also drop out], so that the voters can focus on a limited number of candidates who can offer a positive, conservative alternative to the current frontrunner."
The process to whittle down the field has taken longer than the Cruz campaign anticipated. It banked on going toe-to-toe with solely Trump by March 15, but with John Kasich still in the race, the campaign is in a dogged fight to at least take the nomination fight to the floor of the Republican convention in July.
Walker said in the radio interview on Tuesday that he believes a victory in Wisconsin would put Cruz "firmly in the path to getting the 1237 delegate votes required to win the nomination."
The Cruz campaign brought onboard several top Walker hands, including former top adviser David Polyansky, this fall after the Wisconsin governor dropped out in September.
Walker has stayed out of the presidential limelight since his failed bid and instead focused on Wisconsin. But Cruz hopes his endorsement is beneficial. He's a controversial governor there who is serving in his second term.
In his own presidential bid, his financial fortune turned into misfortune as quickly as his poll numbers dropped. He hired too quickly and spent too much money and was unable to stay afloat in the crowded presidential field.