President Trump’s political operation has unleashed its vast financial resources to try to save the Republican Party’s control of Congress, reserving nearly $138 million over the past 10 days to help the party’s midterm candidates. The planned spending linked to Mr. Trump’s $400 million super PAC, MAGA Inc., has grown by the day, and is set to fuel a massive ad campaign supporting battleground Republican candidates beginning this month. Some Republicans for months have criticized MAGA Inc. for not seriously engaging in the midterms despite its huge war chest. But now a blitz of spending tied to the group has arrived.

A new super PAC that The New York Times previously reported was linked to MAGA Inc., No Going Back PAC Inc., has booked over $95 million worth of ads, according to data from Ad Impact, a media tracking firm. Another $27 million worth of ads is slated to come from another new super PAC called Safety and Affordability PAC Inc. The group is financially backed by MAGA Inc., according to two people with knowledge of the matter, who spoke on the condition of anonymity to disclose a confidential arrangement. The group has not yet begun advertising.

The three super PACs seem to have essentially carved up the midterm map; so far, their only overlapping advertising spending is in just two House races, New York’s 17th District and Michigan’s 4th District. In addition to the ad reservations, the super PACs have also spent about $6.5 million on direct-mail efforts and about $80,000 on text messages, according to F.E.C. records. Together, the three groups are slated to spend about $138 million on ads, mail and texts to help Republican candidates in about 50 general-election races, spending the most on Senate contests in Michigan, Ohio and Alaska.

The two newer super PACs appear to be so-called pop-up groups, appearing late in an election cycle and spending heavily before they are legally required to disclose their donors. The two groups were formed in quick succession on Sept. 1 by Charles Gantt, a Republican political operative who specializes in campaign finance, according to F.E.C. disclosures.