Proposing a broad package of taxes in the midst of a prolonged recession should only be done with extreme trepidation — and months of careful planning.

Unfortunately for Gov. Martin O’Malley, he forgot to focus on the basics and instead surprised legislators with a bunch of poorly received tax ideas.

A whopping gas tax increase, as much as 21 cents, phased in over three years. Substantial tax increases for many middle-income families with two wage-earners. A doubling of the water and sewer fee (flush tax) that pays for treatment plants upgrades.

In the best of times, with a compliant legislature, discussion of such an array of higher taxes would be controversial.

But 2012 is not the best of times. It’s a terrible moment to dump a truckload of hated taxes on Marylanders.

State Democrats must feel blindsided. Their titular leader is proposing politically explosive tax changes — yet he didn’t engage in deep consultations before announcing his plans.

A recent Washington Post poll shows 70 percent against a 10-cent gas tax increase. (Another poll puts the opposition at 75 percent.) O’Malley’s tax hike is twice that size.

The governor has badly miscalculated.

Instead of spending his time developing a national reputation as chair of the Democratic Governors Association, he should have devoted the past six months to discussions with legislators to develop a consensus on tax policies.

He never prepared lawmakers for this spate of unexpected tax changes.

He didn’t fully vet his controversial gasoline sales tax, a concept that was abandoned by his own blue-ribbon commission on transportation revenue.

He never tested out on legislators the notion of reduced income tax personal exemptions and itemized deductions — and thus higher taxes — for many of Maryland’s two-income, middle-class families.

If he had, he would have dropped both ideas, or at least engaged in tough give-and-take to devise more realistic options.

O’Malley kept lawmakers in the dark. Most of them learned about his sales-tax-on-gasoline plan when the governor mentioned it in a radio interview this week.

The irony is that both extending the sales tax to gasoline and reducing tax breaks for families earning over $100,000 annually make sense as tax policy.

A gradual phase-out of some tax breaks for more affluent wage-earners would add progressivity to the Maryland tax code.

A sales tax on motor vehicle fuel, in addition to a flat fee, already is the law in seven states. It allows the transportation department to compensate for inflation — a key missing ingredient.

After 20 years of no gas tax hikes, the transportation department is close to running on fumes. More revenue is a must.

But O’Malley’s surprise proposal won’t pass as introduced.

For one thing, a three-year phase-in means legislators will be adding another six to eight cents to the gas levy in 2014 — when they’re running for re-election.

That’s a political nightmare for any Democrat considering another term in the State House.

It will be up to Senate President Mike Miller and House Speaker Mike Busch to make the governor look good. They’ve done it before for other Democratic governors who submitted unrealistic proposals. They’ll find a way this time, too.

It’s likely that legislators will deconstruct O’Malley’s tax proposals and then rebuild them in more politically astute ways.

For instance, the phase-out of personal exemptions and itemized deductions might be revised so it only affects higher-income families, perhaps in the $250,000 and above range.

Similarly, the governor’s sales-tax-on-gasoline plan could be reshaped and reduced in scope to help Miller and Busch round up the votes for passage.

Miller is in better position to secure Senate approval for a large gas-tax increase (he’s advocated such a move for years), but Busch faces a challenge in the House, where passage is more problematic.

A combination of a smaller sales tax applied to gasoline and higher motor vehicle fees might prove a better mix. Also, a shorter phase-in period would avoid a gas tax hike just before the 2014 elections.

Revenue action this session always made sense, since legislators don’t face voters for nearly three years.

Besides, Maryland needs to get its fiscal house in order.

Adjustments to the income tax, even if limited to affluent Marylanders, would shrink the state’s $1 billion structural deficit over time. Other small adjustments to the sales tax proposed by O’Malley accomplish the same thing.

Meanwhile a gas tax increase, whatever its final shape, is critical to Maryland’s economic recovery.

Pumping $500 million or $600 million a year into the transportation trust fund would mean a big boost in construction projects for highways, bridges and mass transit lines.

That translates into lots of good-paying jobs and a much-needed boost to Maryland’s hard-hit builders.

Make no mistake: Higher taxes are coming in 2012. But by the time the legislature passes a budget in early April, the composition of those tax increases could look quite different.

Although the governor has started the tax ball rolling, he may not have much leverage in determining the final outcome.

Barry Rascovar is a State House columnist, a communications consultant and a radio commentator on WYPR-FM, 88.1. He can be contacted at brascovar@hotmail.com.