Tea party favorite Ted Cruz portrays himself as a Washington outsider, but the Texas senator is attracting Beltway money for his 2016 presidential run.

Prominent Republicans Charles and Debra Cooper sent out invitations this week for an April 29 fundraiser at their Washington penthouse apartment, asking donors to commit to raising $10,800 for the Cruz's presidential campaign committee.

Charles Cooper was a top appointee in the Reagan Justice Department and is chairman of the Cooper & Kirk law firm, where he developed a specialty in commercial and civil rights cases. He defended California's Proposition Eight outlawing same-sex marriage when that case came before the U.S. Supreme Court. In the 1990s, Cruz worked for Cooper's firm.

The event provides another example of Cruz's multifaceted approach to politics and fundraising. His positions on issues ranging from the debt ceiling and the Export-Import bank have put him at odds with corporate leaders in the GOP, including the U.S. Chamber of Commerce, which generally backs Republican candidates.

But he also has cultivated strong ties with financiers, particularly in New York and Texas. A network of super PACs formed this week to support Cruz's candidacy announced it would have $31 million in the bank by Friday, a stunning amount that immediately vaults Cruz into the top tier of the GOP field.

The Cooper fundraiser is tied to Cruz's presidential campaign fund, which can accept only limited hard-dollar donations.

The event invites donors to contribute to the official campaign in selected tiers. After the $10,800 "host committee" level, donors are invited to give $1,500 per person to attend a VIP reception. Individuals writing  a check for $500 can attend the "general reception" which, according to the invitation, begins a half hour after the VIP reception.

The maximum contribution that individuals can make to a presidential campaign is $5,400.  Couples are allowed to write a single check for $10,800.