Indiana Gov. Mike Pence will make a “significant” Republican Presidential primary announcement this afternoon, Breitbart News has learned.

Gov. Pence is scheduled to join the “Garrison” show, a popular conservative talk radio show hosted by Greg Garrison on WIBC in Indianapolis.

Donald Trump, Sen. Ted Cruz and Ohio Gov. John Kasich have all met with Pence recently, seeking his endorsement ahead of the pivotal Indiana primary on Tuesday. Pence is popular with Hoosier Republicans, drawing support from all wings of the party.

Public polling currently gives Trump a slight edge in Indiana, but private polling rates the contest as a toss-up, Breitbart News has learned.

Trump has dominated the Republican primary for the past two weeks, with landslide victories in his home state of New York and a handful of Northeastern states earlier this week.

The Indiana primary tees up the remainder of the Republican contests, which will take place largely in the Midwest, Plains and West. These are regions where Trump and his principal challenger, Sen. Cruz have run much more competitively.

A Trump victory in Indiana, claiming the lion-share of its 57 winner-take-most delegates, is critical to his hopes of securing the necessary 1,237 delegates necessary to win the nomination ahead of the RNC convention. Building on his recent momentum, it would likely cement his status as the presumptive nominee for Republicans nationwide.

A loss in Indiana would likely leave Trump a few dozen short of an outright majority of pledged delegates for the nomination. It would set off a scramble to win the support of convention delegates who aren’t bound to any particular candidate.

A Pence endorsement for any of the three candidates could reshuffle the race in Indiana as the contest enters its final weekend.