By James Oliphant
WASHINGTON (Reuters) - The escalating, increasingly personal feud between U.S. Republican presidential candidates Donald Trump and Ted Cruz over their spouses drew criticism on Thursday from a top lawmaker who said he had enough of the sophomoric taunts between the two.
"Talk about things that people really care about, and knock this crap off because these are serious times, and you're not behaving like you want to be president of the United States," Senator Lindsey Graham of South Carolina, said on NBC's "Today" show.
"You're behaving like you're on a reality TV show," said Graham, who has come out in support of Cruz.
Trump responded by lobbing insults on Twitter at Graham, whose presidential bid failed to catch fire.
Earlier this week, an anti-Trump Super PAC, Make America Awesome, published an ad featuring a photo of Trump's wife Melania lounging nude. Trump then threatened to "spill the beans" on Cruz's wife.
"Donald, real men don't attack women. Your wife is lovely, and Heidi is the love of my life," Cruz said in a post on Twitter early on Thursday.
His tweet followed one moments earlier by Trump, the Republican front-runner in the race, in which he retweeted an image featuring a less-than-flattering picture of Heidi Cruz juxtaposed with a glamorous photo of Melania.
Cruz has denied having anything to do with the nude photo, blaming it on the Super PAC, with which he has no affiliation.
The director of Make America Awesome, Liz Mair, posted on Twitter on Wednesday that her group was responsible for the ad. She did not respond to an email from Reuters seeking comment.
The war of words comes on the heels of the candidates' split win on Tuesday. Trump won Arizona and Cruz took Utah in the latest state primary contests to pick a candidate for the Nov. 8 presidential election.
For Trump, attacking another candidate's wife may carry some political risk.
Half of U.S. women say they have a "very unfavorable" view of the billionaire businessman, according to Reuters/Ipsos polling in March.
Cruz fared better, with 24 percent of the 5,000 women surveyed saying they had a "very unfavorable" view of him.
The Democratic front-runner, Hillary Clinton, did worse than Cruz but better than Trump, with 36 percent of women polled saying they had a "very unfavorable" view of her. The poll had a credibility interval of 2 percentage points.
Both Trump and Cruz are trying to garner enough delegates to win the Republican nomination ahead of the party's convention this summer. After Tuesday's contests, Trump had 739 of the 1,237 delegates needed to win the nomination, according to The Associated Press. Cruz had 465.
Ohio Governor John Kasich is also in the running, but so far has only won his home state. He has 143 delegates.
Cruz, a U.S. senator from Texas, is a staunch social conservative and a divisive figure in the party due to his willingness to criticize the leadership and his prominent role in bringing about a 2013 government shutdown.
But he is still seen by party grandees and many Republicans in Congress as preferable to Trump, who is viewed as straying even further from party principles.
Both candidates are trying to line up more support, including endorsements from the dozen or so candidates who have dropped out of the race, to nail down votes ahead of a potential showdown at the convention in Cleveland in July.
On Wednesday, Cruz won the backing of former rival Jeb Bush as prominent Republicans overcome their aversion to the conservative senator.
The next Republican contests will be on April 5 in Wisconsin and on April 9 in Wyoming.
(Reporting by Megan Cassella and Susan Heavey; Editing by Jeffrey Benkoe and Jonathan Oatis)