A person who argues to defend or justify some policy or institution:
— An apologist for capital punishment.

synonyms: justifier, vindicator.

Roget 937: vindication, justification, warrant; exoneration, exculpation; acquittal etc. 970; whitewashing.    extenuation; palliation, palliative; softening, mitigation.    reply, defense; recrimination etc. 938.    apology, gloss, varnish; plea etc. 617; salvo; excuse, extenuating circumstances; allowance, allowance to be made; locus paenitentiae [Lat.].    apologist, vindicator, justifier; defendant etc. 938.    justifiable charge, true bill.    v.. justify, warrant; be an excuse for etc. n.; lend a color, furnish a handle; vindicate; exculpate, disculpate^†; acquit etc. 970; clear, set right, exonerate, whitewash; clear the skirts of.    extenuate, palliate, excuse, soften, apologize, varnish, slur, gloze; put a gloss, put a good face upon; mince; gloss over, bolster up, help a lame dog over a stile.    advocate, defend, plead one's cause; stand up for, stick up for, speak up for; contend for, speak for; bear out, keep in countenance, support; plead &c., 617; say in defense; plead ignorance; confess and avoid, propugn^†, put in a good word for.    take the will for the deed, make allowance for, give credit for, do justice to; give one his due, give the Devil his due.    make good; prove the truth of, prove one's case; be justified by the event.    ... show more

Dutch: apologeet
Polish: chorąży