AP Photo/Rick Bowmer Former Republican presidential candidate Mitt Romney weighs in on the 2016 presidential race during a speech at the the University of Utah.

Mitt Romney, who won the Republican nomination in the 2012 election, is back in the news this campaign cycle, appearing on news programs to advocate against Donald Trump and robocalling voters on behalf of Trump's rivals.

But Romney's star within the GOP has faded considerably since his presidential campaign, according to a new HuffPost/YouGov poll.

Just before the 2012 election, Romney's favorability rating among Republicans stood at 86 percent. But that number has sunk to 46 percent, according to the most recent poll.

Trump, by contrast, garners a relatively healthy 57 percent. Asked which man they'd prefer as president, Republicans choose Trump by a 5-point margin, giving him 44 percent to Romney's 39 percent.

A substantial minority of the GOP, like Romney, is concerned about Trump. About one-third agree that Trump is a "phony" and a "fraud," and 40 percent call him "dangerous."

The word more people seem to attach to Trump, however, is "electable."

Sixty-two percent of Republicans say Trump would have a better chance than Romney of winning this year's general election if he were the GOP nominee. Just 21 percent see Romney, who already lost once, as having a better shot.

As other polling has already suggested, Romney's clout is even more limited among Trump supporters.

The majority of Republicans who hope to see Trump nominated also say they voted for Romney four years ago. However, just 23 percent of those Trump supporters have a positive opinion of Romney today.

Romney's cri de coeur, instead, has played best among a different audience: Democrats. Members of the opposing party prefer Romney over Trump by a 35-point margin, 53 percent to 18 percent. Seventy-one percent agree with Romney that Trump is a phony and fraud, with more than three-quarters calling Trump dangerous.

Independents also express overwhelming dislike toward Trump, meaning the nation as a whole thinks Romney has a point.

Romney's favorability rating among all Americans is just 27 percent, but a majority believe he's right to consider Trump a phony and a fraud, and 57 percent agree that Trump would be dangerous as a leader.

YouGov

If Trump ends up being the Republican nominee, it's easy to see Romney's denunciation turning into a Democratic attack ad. As a way to change the course of the Republican primary, though, it doesn't promise to be quite as effective.

The HuffPost/YouGov poll consisted of 1,000 completed interviews conducted March 3-6 among U.S. adults, using a sample selected from YouGov's opt-in online panel to match the demographics and other characteristics of the adult U.S. population.

The Huffington Post has teamed up with YouGov to conduct daily opinion polls.You can learn more about this project and take part in YouGov's nationally representative opinion polling. Data from all HuffPost/YouGov polls can be found here. More details on the polls' methodology are available here.

Most surveys report a margin of error that represents some, but not all, potential survey errors. YouGov's reports include a model-based margin of error, which rests on a specific set of statistical assumptions about the selected sample, rather than the standard methodology for random probability sampling. If these assumptions are wrong, the model-based margin of error may also be inaccurate. Click here for a more detailed explanation of the model-based margin of error.