A conservative group is launching a $1.5 million advertising blitz aimed at helping presidential hopeful Ted Cruz Rafael (Ted) Edward CruzSenate Republicans face tough decision on replacing Ginsburg Cruz: Trump should nominate a Supreme Court justice next week Renewed focus on Trump's Supreme Court list after Ginsburg's death MORE halt rival Donald Trump Donald John TrumpObama calls on Senate not to fill Ginsburg's vacancy until after election Planned Parenthood: 'The fate of our rights' depends on Ginsburg replacement Progressive group to spend M in ad campaign on Supreme Court vacancy MORE’s momentum in Indiana.

The Club for Growth on Friday began airing a 30-second spot in the state arguing Cruz is the only candidate capable of keeping Trump from winning the GOP nomination.

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“If you don’t want Donald Trump to win, your choice comes down to this: math,” a narrator in the ad says. "Only Ted Cruz can beat Donald Trump. John Kasich can’t do it. The math won’t work.

“A vote for Kasich actually helps Trump by dividing the opposition. It’s time to put differences aside. To stop Trump, vote for Cruz.”

The new clip will run on digital platforms and TV outlets in Indiana between now and the Hoosier State’s GOP presidential primary on May 3.

“With his responses to every new issue Donald Trump demonstrates that he is really a hardcore liberal,” Club for Growth President David McIntosh said in a statement released Thursday.

“The polls show that he would be beaten badly in November, and the fallout would spread to House and Senate races, and ultimately the Supreme Court,” he added. "There is no state more important than Indiana for electing Cruz and keeping Trump from reaching 1,237 [delegates].”

Club for Growth’s new ad follows a similar campaign in Wisconsin, where Cruz won the GOP primary.

Club for Growth’s political arm backed Cruz before that contest, making its first-ever presidential primary endorsement.

The conservative organization has previously targeted Trump’s healthcare platform and his rhetoric concerning women earlier this election cycle.

Trump has a nearly 10-point edge over Cruz and Kasich nationwide, according to the latest RealClearPolitics average of polls. He also leads the pair in delegates, with 845 to Cruz’s 559 and Kasich’s 148, according to The Associated Press.

A candidate needs at least 1,237 delegates to avoid a contested Republican National Convention in July. Indiana awards 57 delegates.