Just as he’s set to officially clinch the GOP nomination in Texas today, Mitt Romney has a new Donald “Birther” Trump problem.  Romney has had many chances to repudiate the real estate mogul and reality television star for his disturbing obsession with the president’s birth certificate, but so far Romney, who has yet to stand up to the fringe elements of his party, has again wimped out.

Romney’s campaign is out promoting their joint fundraiser with Trump in Las Vegas tonight, leaving many to wonder why the GOP nominee can’t stand up to The Donald.  It’s possible Romney has done the math and thinks he would lose more “birther” support in the GOP and Tea Party base if he were to denounce Trump.  These losses could hurt the Romney campaign more than any benefit he may receive as a result of rejecting birtherism.  Certainly any futile attempt by Romney to attract black voters would not work.  The Romney campaign has likely considered potential losses among independent and swing state voters their Trump association may cause, but that is not outweighed by the candidate’s need to garner support among the Tea Party base that loves Trump and is only lukewarm to Romney, at best.

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When Romney was asked about his association with the radioactive Trump, Romney said, “You know, I don’t agree with all the people who support me and my guess is they don’t all agree with everything I believe in. But I need to get 50.1 percent or more and I’m appreciative to have the help of a lot of good people.”

Ignoring the small detail that winning 50.1 percent doesn’t actually mean that Romney will win the election, this statement by the GOP nominee is certainly an illustration of his campaign’s cynical approach to the race.  Their strategy appears to be: always lurching to the right, flip-flopping from previously held positions to win a primary over much more conservative candidates, and grinning alongside anyone who is willing to fund and support his campaign.  Trump should be out of the picture: other candidates with more conviction would have pushed him well out of the spotlight by now.  But Romney continues to hold on tight to Trump’s support, even as he continues to rant about President Obama’s birth certificate, determined to be the last birther standing.

The Obama campaign certainly isn’t going to let Romney’s association with Trump slide.  They released a web video comparing candidate John McCain’s willingness to stand up to false claims and conspiracy theories about the president back in 2008.  That is paired with footage of Trump and his birther conspiracy nonsense pointing out that Mitt Romney is not willing to stand up to Trump and denounce his racially charged attacks on President Obama.  At this point it’s a reflection on Romney’s lack of a core and the courage to stand up for what’s right.

After Romney reaffirmed his support, Trump doubled down, offering up “new” evidence that the president has been lying about where he was born and the release of the short and long form certified copies of the birth certificate isn’t enough to change his mind.  Trump told CNBC, “I never really changed — nothing’s changed my mind. And by the way, you know, you have a huge group of people. I walk down the street and people are screaming, ‘Please don’t give that up.’ Look, a publisher came out last week and had a statement about Obama given to them by Obama when he was doing a book as a young man a number of years ago in the ’90s: ‘Born in Kenya and raised in Indonesia.” This claim has been repeatedly and definitively proven false.  But, as with most conspiracies, evidence proving the conspiracy false doesn’t help the conspiracy die.

Romney’s association with Trump is unacceptable, especially considering recent media-driven “controversies,” including the flap over Hilary Rosen’s comments about stay-at-home moms and Ann Romney.  Rosen, who is not affiliated in any official capacity with the Obama campaign, was forced to apologize, and even the president was drawn into the dust-up and asked to condemn her comments (which he did).

Then there’s the guilt by association tactic used against the president with statements made by comedian Bill Maher, who is only a donor to Obama’s Super Pac, not a surrogate like Trump.  Trump and Romney are doing a joint fundraiser, there are hints that there might be a Super PAC in Trump’s name to support Romney’s efforts and the Celebrity Apprentice star has been featured in Romneys’ ads.  It’s time Romney is called to task for this troubling relationship.

Trump isn’t popular, his birther beliefs are far outside of the mainstream, and his theatrics create a media spectacle that Romney should want to avoid.  Mitt Romney needs to use this as an opportunity to show he has core principles and the conviction to stand up to these types of attacks on the president; otherwise, it will be further evidence that he will stand for anything.

Follow Zerlina Maxwell on Twitter at @zerlinamaxwell