Groups supporting Ted Cruz spent close to $30 million last month as the first presidential nominating contests got underway and the U.S. senator from Texas sought to position himself as the GOP's chief alternative to frontrunner Donald Trump. 

That's according to disclosures made Sunday with the Federal Election Commission by eight organizations seeking to put Cruz in the White House, including his campaign. All told, the constellation of pro-Cruz entities raised $18.4 million in February, spent $29.1 million and entered March with $28.5 million in the bank.

Cruz's campaign was the biggest spender of the bunch, unloading $17.5 million in its costliest month yet. The campaign raised $11.9 million in February and ended the month with $8 million cash on hand, estimates of which were previously released by the campaign. 

The figures accounted for Feb. 1 through Feb. 29, a period that began with the first-in-the-nation caucus in Iowa and included three more nominating contests. Cruz's campaign and the outside groups supporting him spent millions of dollars on media during the time frame, seeking to boost the candidate on TV, radio and the Internet. Cruz's campaign alone reported doing more than $8 million of business with Memphis-based advertising firm WestRogers LLC.

The Texas Tribune thanks its sponsors. Become one.

In February, the most financially active of the super PACs backing Cruz was Stand for Truth, a relatively new addition to the universe of pro-Cruz outside groups that has earned the blessing of Cruz's high command. Stand for Truth raised $3.9 million, including $1 million from Florida retiree Gale Alger, the wife of investment firm founder Fred Alger, and hundreds of thousands of dollars from prominent Texas donors such as Lee Roy Mitchell, Robert Marling and James McIngvale.

The original cluster of pro-Cruz super PACs, each named some variation of "Keep the Promise," ramped up their fundraising activity in February after doing little in previous months to build on their initial multimillion-dollar donations. Keep the Promise PAC, Keep the Promise I and Keep the Promise III collectively raised $2 million, while Keep the Promise II continued to take in nothing. 

The $2 million haul by the three Keep the Promise groups was powered by a $500,000 donation to Keep the Promise I by Robert Mercer, the New York hedge fund billionaire who gave the same group $11 million upon its formation. Another top donor to the Keep the Promise network in February was James Leininger, who gave $250,000 to Keep the Promise III. Leininger, a San Antonio businessman and longtime supporter of former Gov. Rick Perry, was added to the Cruz campaign's national finance team earlier this month.

February saw the birth of two additions to the Keep the Promise network: Trusted Leadership PAC and Keep the Promise to Veterans. Trusted Leadership PAC, which was created to help raise money for the groups under the umbrella, brought in $200,000, half of it from John Childs, a Boston private equity investor who has previously given to Cruz, and a company tied to Midland oil executive Kyle Stallings. The veterans group, which is being led by Perry, raised $400,000 from three donors who are not new to financially supporting Cruz or Perry: Dallas tech tycoon Darwin Deason ($200,000), Dallas tax consultant G. Brint Ryan ($100,000) and Houston energy investor Toby Neugebauer ($100,000).

Heading into March, more than $20 million of the cash available to help Cruz was stored in his supportive super PACs. Keep the Promise II and Keep the Promise III were leading the way, with $9 million and $9.4 million in the bank, respectively. Keep the Promise II was founded with a $10 million donation from Neugebauer, while Keep the Promise III was started with contributions totaling $15 million from the families of Dan and Farris Wilks, brothers who made their billions in the West Texas fracking boom.

Financial resources are becoming increasingly important for Cruz, who is planning a long-haul battle against Trump for the Republican nomination. Trump has invested nearly $25 million of his own money in his campaign, $6.9 million of which he loaned to it last month. The billionaire's campaign had $1.3 million cash on hand as it entered March after spending $9.5 million the previous month. 

The Texas Tribune thanks its sponsors. Become one.

The only other Republican candidate left in the race, John Kasich, is badly trailing Cruz in the money race. The campaign of Kasich, the Ohio governor, raised $3.4 million in February and entered March with $1.3 million in the bank. The main super PAC supporting Kasich, New Day for America, reported taking in $3.2 million last month and having $2.5 million cash on hand. 

Additional reporting by Matea Gold of The Washington Post.