(CNN) Former Republican presidential nominee Mitt Romney launched a blistering attack on Donald Trump. In an effort to change the dynamic of this primary season, Romney offered blistering words, characterizing Trump as a "fraud" and a "phony" who needed to be stopped. He said that Trump was "playing the American public for suckers."

"His promises are as worthless as a degree from Trump University," the 2012 candidate said. "He has neither the temperament or the judgment to be president." While he encouraged primary voters to vote for any of Trump's remaining challengers, there's a real question about whether an attack from Romney, as an embodiment of the GOP establishment, will help the Republican frontrunner more than it hurts him.

Romney's father and Goldwater

This is not the first time a Romney has taken a powerful stab at the Republican frontrunner. In 1964, his father, Michigan Gov. George Romney, blasted his party's decision to nominate Arizona Sen. Barry Goldwater.

George Romney predicted presciently that Goldwater's candidacy would be devastating to the GOP, a party where northern moderates still played a huge role in the electorate and the party leadership. One of George Romney's sharpest critiques of the Arizona senator revolved around his opposition to the Civil Rights Act of 1964, a position that Romney couldn't understand. "A 'no' vote on civil rights certainly indicates," he said, "that Goldwater's views in this vital area are not in accord with the sentiment of the majority of the public, the majority of Republicans, the majority of Congress..."

Governor Romney had strong support from his colleagues. A majority of Republican governors agreed with him. There were many supporters who wanted Romney to run, though the governor had promised that he would not do this in 1964 so that he could work on the problems of his state.

Though he wasn't the nominee, Romney worked hard to make sure that the GOP included a strong civil rights plank in the party platform. He avoided endorsing Goldwater, to the dismay of conservatives. When one Goldwater supporter approached Romney to request his support, according to historian Rick Perlstein, he received "nothing but a bitter stare."

George Romney's opposition didn't stop. Romney did almost nothing to support Goldwater's campaign. One Lyndon Johnson ad quoted Romney as saying that Goldwater's nomination would lead to the "suicidal destruction of the Republican Party." The two men didn't appear together. Romney won his own re-election bid despite divorcing himself from the party's nominee, and the governor's victory was a landslide.

What's different now?

The difference between the opposition of son and father says a lot about how the Republican Party has changed. When George Romney took on Barry Goldwater, his opposition was largely about principle, not personality. Even when thinking about his own re-election, he realized that Republicans needed candidates who could appeal beyond the right.

The future of the party, in his mind, depended on a diverse coalition that brought together conservatives, moderates and progressives around the ideas of limited government, tough national security, and an embrace of racial equality.

The speech by his son was very different. The Republican Party has shifted far to the right since 1964. Even Barry Goldwater would probably be considered to be too tame by today's tea party standards. There are very few genuine moderates in the party anymore. Those who we consider moderate today were on the right wing just about a decade ago.

Mitt Romney's speech says nothing about the kind of arguments that his father made. His main critique of Trump is that he is too liberal, that he is a Democrat hiding in Republican clothes.

In fact, he ironically started by citing Ronald Reagan's speech in favor of Barry Goldwater during that campaign. Unlike 1964, this Romney is arguing that the party needs to make certain there is no move away from the Republican orthodoxy on issues like health care and taxation. Though Romney attacked particular parts of Trump's hawkish statements about ISIS, the fact is that both are part of a GOP that has embraced a muscular and highly aggressive militaristic approach to dealing with terrorist threats.

His other major complaint simply had to do with style and approach. He doesn't like the kind of smashmouth politics that Trump embraces, which he thinks is unfitting for his party. The problem is that this style is not simply an invention of Trump.

Since their emergence in 2008, tea party Republicans, with Sarah Palin, the vice presidential nominee, as practitioner have embraced this kind of confrontational, aggressive and provocative campaign style that Trump is taking to new levels. We have also seen this in the House of Representatives, where Freedom Caucus members have gone to great lengths to lower the bar for pursuing conservative goals.

Too late?

Romney's criticism of Trump's statements about Muslims, immigrants, and race comes too late given the way in which hard-line elements on these issues have been taking a hold on the party for many years already. Party leaders have not done enough to push back against these kinds of statements and now it is coming back to bite them. While Romney did speak in strongly critical fashion about Trump's interview with CNN's Jake Tapper about the KKK, he and other Republican leaders have not devoted nearly enough energy to reprimanding and denouncing fringe elements of the Republican Party that have played to racial sentiment in their attacks on the first African-American president. Trump came from somewhere. Indeed, as Trump has reminded the press, Romney sought his support in 2012 despite the real estate mogul being the leading voice of the 'birther" movement which attempted to de-legitimize President Barack Obama.

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For this reason, Romney's attack could easily play right into Trump's hands. His attack on style will be seen as an implicit critique of the anti-establishment politics that the Freedom Party embraces.

To have Romney criticize Trump in this way is to fuel a narrative on the right of a party that is trying to stifle the only genuine voice that exists. Many Republicans will hear Romney, the symbol of the 1%, attacking Trump's criticism of free trade and double down on their support of this insurgent campaign.

Mitt Romney's attacks on Donald Trump are nothing compared to what his father did. Many decades ago, his father took a stand for a party that would be ideologically diverse and where the center and right would both have a place at the table. His son, standing in the shadow of Ronald Reagan and Newt Gingrich, is calling for his party to be more ideologically pure and insisting on a civil style of politics that no longer has much of a hold on many Republicans.