Rand Paul appears to be simply one of the Koch brothers political beauty contest presidential nominees.

Rand, Ted Cruz, Marco Rubio and. Scott Walker have all received  invitations to speak to the Koch brothers' big buck camapign donors event that will be held by Charles and David Koch, reports Politico.

The meeting is set to be held at a Palm Springs hotel this weekend. The name of the actual hotel is a closely guarded secret and the event in the past has included heavy security at the venue to keep out the uninvited.

UPDATE

NYT weighs in and discusses the event:

Perhaps no organization commands more deference in Republican politics nowadays than the sprawling operation established by the Koch brothers. And this week, the intense competition among Republicans for their embrace and attention will break out into the open. An invitation-only group of 2016 hopefuls will travel to a resort near Palm Springs, Calif., for the Koch brothers' annual winter seminar, kicking off the so-called Koch primary...

[T]heir network spans roughly 300 donors, many of whom are wealthy business owners and entrepreneurs, and allows candidates to tap individuals who are conservative but not part of the traditional Republican donor establishment. In 2012, [the Koch-funded]Americans for Prosperity spent more than $120 million in an effort to defeat President Obama and congressional Democrat...

For those with strong relationships in the Koch network, this week's gathering in the California desert will provide a critical early test of the race to win the so-called Koch sweepstakes. The seminar, said Sheila Krumholz, the executive director of the Center for Responsive Politics, is as much for the candidates as for the donors.

"Everyone is on display," Ms. Krumholz said, "either being courted, or being interviewed for the job."