Something that is “like putting lipstick on a pig” is a superficial attempt to cover up someone or something that’s ugly. The expression has been popular in American politics since the last half of the 20th century.
 
“Meretricious as lipstick on a corpse” was printed in The Observer (London, UK) on September 8, 1957. “Like putting lipstick on a corpse” was printed in the Raleigh Register (Beckley, WV) on March 12, 1971.
 
“Like putting lipstick on a pig” was printed in the State-Times (Baton Rouge, LA) on March 6, 1974. “Like putting lipstick on a pig” was printed in Journal Herald (Dayton, OH) on July 19, 1980.
 
The “pig” version is now more popular than the “corpse” version of the lipstick saying.
   
   
Wikipedia: Lipstick on a pig
To put “lipstick on a pig” is a rhetorical expression, used to convey the message that making superficial or cosmetic changes is a futile attempt to disguise the true nature of a product or person. It can be used as a tactic to disguise a strawman argument, especially when invoked to avoid the true meaning of things and justifying conflated definitions that fall into a similar fallacy as a strawman.
 
Wiktionary: put lipstick on a pig
Verb
put lipstick on a pig (third-person singular simple present puts lipstick on a pig, present participle putting lipstick on a pig, simple past and past participle put lipstick on a pig)
1. (idiomatic) To superficially alter something in the hope of making it seem more appealing than it is in actuality.
     
8 September 1957, The Observer (London, UK), “New Fiction: An Outlaw in the West” by Olivia Manning, pg. 13, col. 8:
The bar was fitted in roadhouse Tudor, meretricious as lipstick on a corpse, the insistent strip lighting hanging in mid-air like the smile of a maniac dentist.
 
12 March 1971, Raleigh Register (Beckley, WV), “Tortuous!” (editorial), pg. 4, col. 2:
We did see one small advertisement against stripping, the one that pointed out that reclamation was like putting lipstick on a corpse.
 
13 April 1971, The Courier-Journal (Louisville, KY), ‘Strip-mining devastation escalating, says Hechler” (AP), pg. A16, col. 2:
(Rep. Ken Hechler.—ed.)
Hechler said he is not impressed with reclamation efforts of strip-mined lands and compared such efforts to “putting lipstick on a corpse.”
   
6 March 1974, State-Times (Baton Rouge, LA), “Dr. Landry Ousted From Post As Chairman of Airport Body” by Don Buchanan, pg. 8-A, col. 1:
He urged dipping into $2 million in bond issue proceeds set aside for the new airport site acquisition to make further improvements at Ryan. (Dr. Hypolite—ed.) Landry said, however, that would be “like putting lipstick on a pig. What would you do with it?”
 
19 July 1980, Journal Herald (Dayton, OH), “Makeup doesn’t cover ugly mug” by D. L. Stewart, pg. 4, col. 3:
DETROIT—OK, so maybe it was like putting lipstick on a pig.
 
But, for one week at least, Detroit whipped out its cosmetics and managed to make itself look almost pretty.
     
16 November 1985, Washington (DC) Post, “San Francisco Tries To Keep Baseball Raiders at Bay: City Fights to Keep Its Giants City” by Jay Mathews,
SAN FRANCISCO, Nov. 15.—KNBR, the AM radio station carrying GIants baseball games, had raised $20,000 toward teh construction of a new downtown stadium. The board of supervisors, reluctant to commit to such a project, asked if they couldn’t use the money to renovate Candlestick Park.
 
“That,” replied KNBR personality Ron Lyons, “would be like putting lipstick on a pig.”
 
17 November 1985, Austin (TX) American-Statesman, pg. J2, col. 1:
“That would be like putting lipstick on a pig.”—San Francisco radio personality Ron Lyons on the idea of renovating Candlestick Park
     
8 January 1986, Austin (TX) American-Statesman, “The PM Report,” pg. 1, col. 1:
Offensive to pigs
Texas Agriculture Commissioner Jim Hightower cooked up some country corn to deliver his criticism of the Reagan administration and outgoing U.S. Agriculture Secretary John Block. “No one is fooled by this purely cosmetic change,” Hightower said. “It’s like putting lipstick on a pig—they still can’t high the ugliness.”
   
11 May 1988, Orlando (FL) Sentinel, “Water managers take fight with muck farmers to court” by Lisanne Renner, pg. D-7, col. 4:
“It’s something like putting lipstick on a hog. It’s pretty, but you’ve still got a hog with lipstick.”
(Spoken by Terry Lewis, a lawyer representing the Zellwood Drainage District.”—ed.)
 
OCLC WorldCat record
Customer Service Is More Than Putting Lipstick on a Pig
Author: James F. Veronesi
Edition/Format: Article Article
Publication: Home Health Care Management & Practice, v19 n1 (12/2006): 58-60
 
Slate
Who First Put “Lipstick on a Pig”?
The origins of the porcine proverb.
By BEN ZIMMER
SEPT 10, 2008 5:37 PM
(...)
Many porcine proverbs describe vain attempts at converting something from ugly to pretty, or from useless to useful. The famous maxim that “You can’t make a silk purse from a sow’s ear” dates back at least to the mid-16th century. Other old sayings play on the ludicrousness of a pig getting dressed up. “A hog in armour is still but a hog” was recorded in 1732 by British physician Thomas Fuller. As Francis Grose later explained in A Classical Dictionary of the Vulgar Tongue (1796), a “hog in armour” alludes to “an awkward or mean looking man or woman, finely dressed.” Charles H. Spurgeon noted another variation in his 1887 compendium of proverbs, The Salt-Cellars: “A hog in a silk waistcoat is still a hog,” meaning, “Circumstances do not alter a man’s nature, nor even his manners.”
 
The “lipstick” variation is relatively novel—not surprising, since the word lipstick itself dates only to 1880.
 
OCLC WorldCat record
Putting lipstick on a pig: the rewrite that will foster the continued hegemony of the culture that already has caused the collapse of the UK economy
Author: T Molloy
Edition/Format: Article Article : English
Publication: TRUSTS AND TRUSTEES, 17, no. 3, (2011): 149-176
 
OCLC WorldCat record
Putting lipstick on a pig : a rep & melissa pennyworth mystery
Author: Michael Bowen
Publisher: Scottsdale, Ariz. : Poisoned Pen Press, 2013.
Edition/Format:   eBook : Document : English
Summary:
Vance Hayes died while joyriding on a snowmobile late one night and breaking through thin ice near the Wisconsin Dells. The cold-hearted, hard-headed lawyer goes unmourned by clients, colleagues, or anyone else’including his reluctant eulogist, fellow attorney Rep Pennyworth. In fact, interest in Hayes’ death is merely perfunctory until it inter-sects with the perils facing charmingly ingenuous Vietnamese-American court reporter Sue Key, tied to Milwaukee’s Hmong community. Could it be that Hayes died not because of any of the rotten and vicious things he spent his career doing to literally hundreds of people, but because of the one decent, human endeavor that marked his adult life’
 
OCLC WorldCat record
Lipstick on a pig : winning in the no-spin era by someone who knows the game
Author: Torie Clarke
Publisher: [Place of publication not identified] : Free Press, 2014.
Edition/Format:   eBook : Document : English
Summary:
Torie Clarke, renowned and respected in political and business circles as one of the nation’s most gifted communicators, offers a complete guide to the new age of transparency. Clarke’s message is refreshing and straightforward: No more spin. Always a dubious proposition, spin has become increasingly vulnerable as information sources have proliferated; spin is simply no longer viable. Or put another way, “You can put lipstick on a pig, but it’s still a pig.” Distilling her twenty-five years of experience and wisdom into eight concise rules, Clarke counsels that politicians and executives need to tell the truth early, often, and in plain language.
   
Twitter
JT 📷
@RunNGunYT
Replying to @Churkh
They can put lipstick on a corpse but it’s still dead if it’s superficial.
10:06 PM - 13 Dec 2018