Some terms come to mind that could describe Vivek and what he is doing on behalf of Pres. Trump:

• A Town Crier, is an officer of a royal court or public authority who makes public pronouncements on behalf of the Royalty
• An Opening Act, is one who warms up the crowd for the Headliner
• A Heralder is one that conveys news or proclaims : announcer, forerunner, precursor, harbinger. One that goes before or announces the coming of another.
• A Presage is an person or thing that forewarns of things to come
• An Ambassador is one who acts as a representative or promoter of a specified person or cause an accredited diplomat sent as an official representative to a person, cause or country
• An Advocate is one who publicly supports or recommends a particular person, cause, or policy
• A Messenger is a person employed to convey official dispatches, messages, instructions or updates as dictated by others above him
• A Surrogate is a substitute, especially a person deputizing for another in a specific role or office
• A Proxy is someone given the power to represent another person

Some terms come to mind that could describe Vivek and what he is doing on behalf of Pres. Trump:

• A Town Crier, is an officer of a royal court or public authority who makes public pronouncements on behalf of the Royalty
• An Opening Act, is one who warms up the crowd for the Headliner
• A Heralder is one that conveys news or proclaims : announcer, forerunner, precursor, harbinger. One that goes before or announces the coming of another.
• A Presage is an person or thing that forewarns of things to come
• An Ambassador is one who acts as a representative or promoter of a specified person or cause an accredited diplomat sent as an official representative to a person, cause or country
• An Advocate is one who publicly supports or recommends a particular person, cause, or policy
• A Messenger is a person employed to convey official dispatches, messages, instructions or updates as dictated by others above him
• A Surrogate is a substitute, especially a person deputizing for another in a specific role or office
• A Proxy is someone given the power to represent another person

Some terms come to mind that could describe Vivek and what he is doing on behalf of Pres. Trump:

• A Town Crier, is an officer of a royal court or public authority who makes public pronouncements on behalf of the Royalty
• An Opening Act, is one who warms up the crowd for the Headliner
• A Heralder is one that conveys news or proclaims : announcer, forerunner, precursor, harbinger. One that goes before or announces the coming of another.
• A Presage is an person or thing that forewarns of things to come
• An Ambassador is one who acts as a representative or promoter of a specified person or cause an accredited diplomat sent as an official representative to a person, cause or country
• An Advocate is one who publicly supports or recommends a particular person, cause, or policy
• A Messenger is a person employed to convey official dispatches, messages, instructions or updates as dictated by others above him
• A Surrogate is a substitute, especially a person deputizing for another in a specific role or office _ A Proxy is someone given the power to represent another person

Some terms come to mind that could describe Vivek and what he is doing on behalf of Pres. Trump:

• A Town Crier, is an officer of a royal court or public authority who makes public pronouncements on behalf of the Royalty
• An Opening Act, is one who warms up the crowd for the Headliner
• A Heralder is one that conveys news or proclaims : announcer, forerunner, precursor, harbinger. One that goes before or announces the coming of another.
• A Presage is an person or thing that forewarns of things to come
• An Ambassador is one who acts as a representative or promoter of a specified person or cause an accredited diplomat sent as an official representative to a person, cause or country
• An Advocate is one who publicly supports or recommends a particular person, cause, or policy
• A Messenger is a person employed to convey official dispatches, messages, instructions or updates as dictated by others above him