The general estimate is that Mitt Romney's acceptance speech did what it had to do.  Romney gave viewers and listeners his human side, gave a stout defense of his business career, and chided -- ever-so-gently -- President Obama for his failures.  Romney employed the soft-touch about Mr. Obama's miserable term in office, we're told, lest he offend some of the president's 2008 voters and independents who are undecided this go-round.

The last is balderdash, mostly peddled by establishment Republicans.  Establishment Republicans are hung up on the president's presumed "likeability" among voters, as if the nation were conducting an election for high school class president. 

The gritty fact is that Americans are made of sterner stuff.  Voters may like Mr. Obama, but they are quite willing to fire him for cause.  Jimmy Carter wasn't disliked by voters back in 1980; they didn't think he was up to the job.  And Ronald Reagan gave voters good reasons, practical and philosophical, to vote for him and against Mr. Carter.  President Reagan created a substantial mandate for change.

The establishment GOP (including some of its conservative elements) has decided that if Romney provides meaty contrasts with the president and indicts him as not merely a well-meaning incompetent, but a hard-edged ideologue whose errant ideology in large part drives his policy failures, then those precious independents may take umbrage.

Well, of course, Romney shouldn't be mean-spirited in making his case against the president.  That doesn't translate to not being tough, though.  And any candidate worth his salt isn't going to attack voters for choices they made in a prior election.  Salesmen don't insult their customers. 

But there are smart ways of separating voters from their earlier choices in candidates without offending.  Namely, by making the case that voters were misled.  That's surely the case with Mr. Obama, who positioned himself as a centrist in 2008 -- a centrist who would fix the economy and pretty much track Bill Clinton, whom many voters still perceive as having governed from the middle.   

What Mr. Obama gave voters in 2008 was blarney, Chicago-style.  He campaigned from the center and has governed on the left -- the programmatic left.  Romney has an obligation to voters to inform them of such.  He needs to educate voters that it's Mr. Obama's worldview and ideas that undergird nearly four years of a torpid economy; that foisted ObamaCare on an unwilling electorate at the price of not reviving the economy; and that has retarded conventional energy development in favor of pie-in-the-sky green energy and to meet the expectations of the primitivist elements among his leftist cohort.  Among many other failures and overreaches driven by the president's leftism.    

If Romney takes to the campaign trail just as Mr. Fix-It -- tackling only the practicalities of Mr. Obama's policy disasters -- then the November election might prove more competitive than need be.  Even if Romney wins riding the tide of a poor economy, his mandate is thinner if he hasn't made the case against Mr. Obama's liberalism (and let's salt in old-fashion Democrat cronyism). 

Dissecting and indicting the president's leftist policies would give a President Romney more heft in scuttling much of the left-wing structure that Mr. Obama and his minions have erected through a long forty-eight months.  The aim for Romney, in fact, is to go deeper; he needs to raze the left's foundations in government as best possible.  At least a President Romney needs to initiate the process of profound reform -- in others words, start the ball rolling toward an historic shift away from the liberal era that has dominated the nation since the 1930s.

Romney's presidential legacy -- if he gets a chance at a legacy -- needs to be marked, enduring change.

No one's suggesting that Romney run a one-dimensional campaign; just banging the drum on Mr. Obama's leftism wouldn't appeal to all voters and most certainly wouldn't paint the entire picture for voters.  But without going after Mr. Obama's liberalism artfully, a critical element will be missing from the picture Romney is creating for voters.    

The common retort to the argument that Romney needs to tackle the president's leftism head-on is that conservative super-PACs and Romney surrogates can do the dirty work (if you consider it dirty work). 

Indeed, super-PACs and Romney surrogates can go bare-knuckles with the president and his Democrats, over ideology and a range of other things.  Romney needn't brawl with the president.  As stated above, he needs to be artful in dissecting the president, indicting his liberalism with a surgeon's touch.  FDR was quite good at opening up his opponents with a smile and, often, humor -- light and biting.  Reagan had the right touch, too, in going after liberals and Democrats.  Then again, Reagan had been a Democrat at one time, so he knew well how to play the game.    

That leads us to the Democrats, whose convention is this week.  Anyone want to wager that Mr. Obama will not continue to define Romney as a heartless plutocrat who is out of touch with working and poor Americans?  Wanna bet that the Democrats use every available opportunity to contrast their "compassion" with Republican and conservative callousness? 

The counter here is that the Democrats are running behind; they need to play offense, as they have been doing.  But the Democrats learned under FDR that a tough offense is the best defense.  If Democrat candidates get out well in front of their GOP opponents, they may cruise, but otherwise, they fight hard and play to win, including going after their opponents' characters and conservatism.  This approach is coded into Democrats' DNA.

And don't underestimate Democrats' relentlessness.  The Party of Government plays politics for keeps.  Mr. Obama and the left have more riding on the November election, in a sense, than Republicans do, in that where do Democrats go when not running government and wielding the power that attends?  What happens to their statist advances that have cost them a bundle in political capital?    

Mr. Obama will hit the campaign trail pounding away at that cruel Mitt Romney, over and over again, knowing that where a lie can't prevail at first, numbing repetition might just do the trick.  Democrats get the value of repetition even in the teeth of initial skepticism. 

Mitt Romney could lose this election if he doesn't employ a full complement of tactics and arguments against retaining Mr. Obama.  Romney doesn't want to wind up the second "Little Man on the Wedding Cake" in GOP annals. 

Romney needs to drag President Obama onto ground favorable to his candidacy.  Americans are instinctively a conservative people.  Mr. Obama's liberalism is a liability, not an advantage, unless he's given the leeway to frame it as he pleases.

This November, Mitt Romney needs to come to bury President Obama's liberalism, not ignore it.