The phrase "legitimate foundation" is correct and usable in written English.
You can use it when discussing the basis or justification for an argument, belief, or system that is valid and credible.
Example: "The research provided a legitimate foundation for the new policy changes."
Alternatives: "valid basis" or "sound groundwork."
Compiling my work into a print and digital portfolio gave me a legitimate foundation to build on.
Though their introduction to opioids had a legitimate foundation, certain vulnerable patients may now be set on a path that could end in dependence or addiction.
Speights serves a worthwhile purpose so long as he isn't asked to do too much, and he puts up numbers in a way that helps his team win without ever providing a legitimate foundation to build upon.
Lawyers for the Unifaun alleged that the board's classification was based on a total misreading of the work and should not form a legitimate foundation for judging the moral standards of a play.
For Hamilton, a legitimate government must protect rights; for Jefferson, "the will of the people is the only legitimate foundation of any government". Jefferson knew that government in a democracy tended to "take away from those who are willing to work and give to those who would not," yet he remained a Democrat his whole life.
Reporters discovered that the money trail wound through some eighteen dummy foundations and twenty-one legitimate foundations.
"The solution has to start by recognising the legitimate foundations of the collective irritation.
(2) It is dependent on something other than itself, a 'normative infrastructure that specifies its lawful foundation and its legitimate objective'.
It has no legitimate political foundation and it is not what the people want.
Sometimes the C.I.A. passed funds through the dummies to legitimate charitable foundations, like the Kaplan Fund, which in turn passed it along to groups like the National Student Association.
There is a legitimate policy-based foundation to Steele's criticism, including the concern (implicitly acknowledged during the president's statement on Thursday) that any tax levied on banks will simply be passed down to shareholders or consumers, as opposed to compelling executives to take smaller bonus packages.
