Mitt Romney holds a rally in Virginia last week, joined by Gov. Bob McDonnell (center) and Rep. Michele Bachmann of Minnesota.

Editor’s Note: David Frum is a contributing editor at Newsweek and The Daily Beast and a CNN contributor. He is the author of seven books, including his new first novel, “Patriots.”

Story highlights

David Frum: On paper, Mitt Romney is well-qualified to be president

He says the problem is that Romney hasn't shown backbone to stick with his positions

He says on issues such as taxes, birth control, gay rights, he yields ground too easily

Frum: If Romney loses, the people whose favor he's currying will blame him

Washington CNN  — 

There is something tragic in the unfolding of Mitt Romney’s campaign for president.

Here is a supremely intelligent and competent man, superbly qualified in so many ways for the highest executive office.

Yet through six years of campaigning for the presidency, he has allowed himself to be remade and redefined by his worst enemies.

David Frum

It happened again last week.

The Romney campaign had hired a new foreign policy spokesman, Richard Grenell, a former aide to then-U.N. ambassador John Bolton.

Grenell is a fierce conservative who is also outspokenly gay. Grenell has taken strong public stances in favor of same-sex marriage. The Romney campaign knew all that when it hired him. Grenell had the competence to do the job, and nothing else mattered. As it shouldn’t.

The hiring came under attack. As attacks go, this wasn’t much: A couple of obnoxious blog posts and a tirade by a local radio host who runs a third-tier social conservative group. Still, the campaign opted to take cover. It reduced Grenell’s visibility, keeping him off a conference call with media where someone might ask about the social-conservative criticism, that kind of thing.

Nobody at the campaign wanted to lose Grenell. In fact, he was repeatedly urged to stay. The campaign only wanted a discreet interval for the fuss to blow over.

The trouble was that Grenell got the job in the first place because he is a fighter. When the campaign wouldn’t fight for him, he decided he wouldn’t fight for it. He resigned. The hiring of Grenell interested only political insiders. His departure detonated one of Romney’s worst news weeks.

Political professionals will remind us that there remain six months to November. By voting day, the Grenell story will have been long forgotten – even by the comparatively small number of people who ever heard of it in the first place.

Maybe. But what a campaign does is paint an image of a candidate in the public mind. The Grenell flap added a stroke to that image: The Romney campaign yields to anti-gay intolerance. That stroke lands on top of other strokes, some fair, others unfair, but all together cohering into an ever-more focused picture.

For example: Romney did not initially support legislation that would allow all employers, religious or not, to drop birth control coverage from their health plans. That was introduced by Marco Rubio. Romney has campaigned with Rubio, and he’s is much discussed as a possible Romney running mate. Although Romney has not made an issue of birth control, he will be wearing the issue in the general election.

A brand is not just something you make. It’s also something that can happen to you if you don’t speak out against it.

Follow @CNNOpinion on Twitter

At times, Romney has foreseen the danger and struggled to avoid it. He never intended to campaign in 2012 as an advocate of additional tax cuts. His carefully crafted economic plan of September 2011 proposed only to perpetuate the Bush tax cuts but nothing more. Through the early Republican primaries, however, Romney came under pressure to offer a bigger bid. 

On the eve of the February 28 Michigan primary, Romney delivered a speech promising a second tax cut on top of the Bush tax cuts to a top rate of 28%. Unlike the elaborate September plan, the February speech was a hasty piece of work.

Even now, the Romney campaign has not offered any estimates of the second tax cut’s effect on the budget deficit. And with the primaries effectively behind him, Romney is suddenly talking about the second tax cut much less. He recognizes that a big tax cut for the wealthiest is not good politics in 2012.

Again, however, he’s stuck.

He’s stuck, too, with his endorsement of the Paul Ryan plan. Romney spent much of 2011 seeking to evade a commitment to the House budget and its one-sided protection of older Americans at the expense of younger Americans. He used formulas about supporting the spirit behind the budget but preferring his own approach.

In December 2011, however, he was finally cornered: If Congress passed the Ryan budget, would he sign it? He said yes – and now he must carry that answer with him into a general election in which young voters will matter more than they do in a Republican primary.

This is not where Romney wanted to be. Yet it’s where he is. And if he loses, the people who pushed him into defeat will be the first to load all the blame for that defeat onto him alone.

But then, perhaps they’ll have a point because it was up to Romney to say no to them – and at the crucial moments, he flinched.

Join us at Facebook/CNNOpinion

The opinions expressed in this commentary are solely those of David Frum.