The phrase "all supportive of the" is correct and usable in written English.
It can be used when describing a group or individuals who are in favor of or provide assistance to a particular idea, cause, or initiative.
Example: "The committee members were all supportive of the new policy changes aimed at improving workplace diversity."
Alternatives: "entirely in favor of the" or "fully backing the".
Comments on the post were all supportive of the service's growth, congratulating Koum and calling the app a "great product".
Since traditional social-democratic and conservative parties are all supportive of the consensus view on austerity (sometimes with a barely audible whisper of criticism), voters can express their dissatisfaction only by voting for extremist, and usually anti-European, parties.
After Bloom quickly warmed to the idea, he asked Primary Wave to make sure that all those with an interest in the deal — Geffen, Love, former Nirvana bandmates Krist Novoselic and Dave Grohl and their managers — were all supportive of the concept.
They were all supportive of the script, of the words.
I took three months to decide to be involved in this, three months where I talked to people who are not all supportive of the government.
Taken together, the RT-PCR, FISH and MS validation tests were all supportive of the exon array findings of massive changes in alternative splicing, in spite of the inherent limitations in each of these methods (e.g. the requirement for tissue preservation, variable primer efficiencies and limited resolution power of peptide sequencing).
However we have a good team spirit, we are all supportive of each other and get through the tough days with good humour.
We're all very supportive of the campaign so we're delighted to be doing this".
"Governors, legislatures, corrections and law enforcement agencies around the country were all very supportive of the act".
The election process "should not be a recruitment of all those supportive of the C.E.O.," said Mr. Naylor, who previously worked for the Teamsters union and is particularly critical of high pay for executives.
The politicians present were all very supportive of the cause, and most promoted their own scientific backgrounds, but we know that politicians with such scientific training are exception rather than the rule.
