Did political donations from the gambling industry make them do it?

That’s the ugly question lingering in the wake of the Maryland government’s move Wednesday to significantly expand casino gambling in the state, assuming that voters okay the plan as expected in a November referendum.

The question arises partly because of unmistakable evidence that the two top politicians who shoved the measure into law are fully aware that gambling hurts the middle-class and low-income people whom their Democratic Party purports to protect.

Both Gov. Martin O’Malley and Senate President Thomas V. “Mike” Miller Jr. have bluntly acknowledged that gambling is a lousy way for governments to raise revenue. It disproportionately drains money from less-affluent classes who bet hoping for a statistically unlikely windfall.

Casino gambling is “a fad, it’s a fancy, it’s wrong, it’s not the way to fund government,” Miller said early Wednesday. He spoke shortly after the General Assembly approved the gambling bill, of which Miller was the most conspicuous champion.

O’Malley gave the plan decisive support even after famously calling gambling a “piss-poor way to advance the common good.”

O’Malley and Miller have consistently said they backed the new casino bill anyway because it’s one of the only ways in the current economy to create jobs and find fresh money for education and other worthy purposes.

But some dissenters, notably Maryland Comptroller Peter Franchot (D), say the Democratic Party has betrayed its base by succumbing to casino industry influence.

“A small group of special-interest folks on the inside, who are largely predatory on the middle class, they get special treatment from Annapolis,” Franchot, a likely candidate for governor in 2014, said in a telephone interview. “You should be appalled at the hijacking of your state government.”

Franchot didn’t single out campaign donations to O’Malley and Miller but instead said that the industry’s influence was generally corrosive.

According to information provided by the government watchdog organization Common Cause, O’Malley received $135,000 between 2006 and 2011 in contributions from casinos, bidders for Maryland casino licenses and horse-racing interests. The amount for Miller during that period was $53,000.

Those aren’t huge numbers for a top state official, but they’re not insignificant. In an apparent sign of sensitivity over the issue, O’Malley’s office told me in a short statement Wednesday that his new, federal political-action committee will not accept “any political contributions related to the gambling expansion in Maryland or casino interests.”

The “O’ Say Can You See” committee is widely seen as designed to support a possible O’Malley run for the presidency in 2016.

The new gambling law backed by O’Malley also bans political contributions in Maryland from gambling companies and anybody owning 5 percent of a casino company. That comes rather late, however: Activists have supported such a clampdown since 2003, and now the state seems set to be saturated with casinos.

“It’s like turning off the faucet in the bathroom once the flooding is done,” said James Browning, regional director for Common Cause.

If voters approve the gambling measure, Maryland’s five authorized slots casinos could add such table games as blackjack and roulette. The new law would also allow a sixth casino to be built in the state, in Prince George’s County.

Anti-gambling activists say events in Maryland reflect a national trend over the past decade in which several Democratic governors have come out in support of casino gambling and received substantial industry contributions.

The Democratic Governors Association received $1.8 million from gambling companies and individuals associated with the industry between 2003 and 2011, according to Common Cause. O’Malley took over as chairman of the association at the end of 2010.

New York Gov. Andrew M. Cuomo (D) was embarrassed in June when the New York Times reported that a group closely allied with him received $2 million from gambling interests as he developed a proposal to expand casino gambling in the state.

Support from Democratic governors like Ed Rendell in Pennsylvania and Steve Beshear in Kentucky led to more casinos opening near big cities and being more convenient for average people.

“What’s new and what’s transformative is the casinos had traditionally been kept away from major population centers, and it’s been the Democratic Party that traditionally has controlled these big population centers,” said Les Bernal, executive director of the Stop Predatory Gambling foundation.

“Now that’s changed. Democrats have basically given the green light to come on in,” Bernal said. “Part of it is campaign money, and part of it is there’s such a quest for revenue.”

Franchot urged Maryland politicians to voluntarily disclose any contributions this year from gambling interests before the special session, but he was ignored. The public should demand they do so before the November referendum.

Before we vote to make such a big change, we ought to know who’s paying for it.

I discuss local issues at 8:51 a.m. Friday on WAMU (88.5 FM). For earlier columns, go to washingtonpost.com/mccartney.