Maryland Gov. Larry Hogan greets supporters before delivering his State of the State address Feb 4. (Steve Ruark/AP)

One of the few specific prom­ises that Maryland Gov. Larry Hogan (R) made on the campaign trail last year was this: If elected, he would kill the much-loathed “rain tax.”

That issue is at the heart of legislation the governor unveiled Tuesday — the first non-budget bill he has touted since taking office three weeks ago. But killing a tax isn’t simple, it turns out. And even if Hogan’s bill passes the Democrat-dominated legislature, Maryland taxpayers shouldn’t expect anything to change right away.

A 2012 Maryland law requires that the state’s 10 most-populous jurisdictions charge their residents a “stormwater remediation fee” that funds removing pollution from rainwater before it reaches the Chesapeake Bay. The fee can range from $15 for a condo owner in Howard County to thousands of dollars for a business in Baltimore County.

Hogan’s bill would lift the requirement that these jurisdictions charge this fee. Local officials would still have to find funding to continue their anti-
pollution efforts, which are mandated by the federal government, and they could choose to continue charging the fee.

“Look, there are some counties — Montgomery County, Prince George’s County, Baltimore City — who want to tax the rain,” Hogan said at a news conference. “This repeal doesn’t take away their right to do so. They’ve always had that right.”

To pass his bill, Hogan will need the cooperation of Democrats — many of whom are not fond of the new governor’s never-ending accusations that their tax-and-spend excesses have driven the state into the ground. He already has the support of the numerous taxpayers who latched onto campaign commercials that attacked Democrats for taxing everything they could, even the rain.

A Washington Post-University of Maryland poll released Tuesday found that 65 percent of residents support reducing the fee. Dislike of the rain tax runs across party lines: 78 percent of Republicans want it gone, along with 68 percent of independents and 58 percent of Democrats.

“The rain tax was the straw that broke the camel’s back, and it ignited a tax revolution in our state,” Hogan said. “It is nearly universally despised by an overwhelming super-majority of taxpayers throughout the entire state.”

Montgomery County — which established its own stormwater management fee system long before the state mandated it — is an exception: Fifty-five percent of its residents said they opposed reducing the fee. A county spokesman said Tuesday that a repeal probably would not affect the county.

While leaders of the Maryland Senate have said that some version of Hogan’s bill will probably pass in their chamber, House of Delegates Speaker Michael E. Busch (D-Anne Arundel) said Tuesday that he is “doubtful” his members will do the same. He said a repeal of the mandate could severely hurt the state’s environmental progress — all to fulfill a catchy campaign promise.

“It’s political rhetoric without a whole lot of substance behind it,” Busch said.

A number of environmental groups criticized the governor’s proposal, saying that allowing counties to eliminate the fees would starve local governments of funds for much-needed programs that have already been successful. Alison Prost, executive director of the Chesapeake Bay Foundation, said the legislation “would send Maryland backwards.”

Hogan brushed off such dissent, saying it represents a “vocal minority of people.” He said that pollution in the bay is a serious issue that he will address, although he has yet to formalize a plan.

While on the campaign trail, Hogan’s lambasting of the rain tax was part of ongoing criticism of the taxes and fees imposed during the tenure of Gov. Martin O’Malley (D). Hogan even gave donors black umbrellas labeled: “Who’ll stop the rain (tax)?”

Now that he’s governor, Hogan has focused on how the mandated fee takes power away from local jurisdictions. “Forcing certain counties to raise taxes against their will on their citizens was a mistake that needs to be corrected,” Hogan said.

Proponents of the fees say there is already an enormous amount of flexibility in the law. Only 10 of the state’s 24 jurisdictions are required to have a fee, and local officials can decide how it’s set and how the money is spent.

Carroll County received permission to not charge a fee, while Frederick County charges only a penny. Harford County leaders recently repealed their fee, while Baltimore County Executive Kevin Kamenetz (D) has proposed reducing his county’s fee.

Some Democrats have decided this isn’t a battle they want to fight. Maryland Senate President Thomas V. Mike Miller Jr. (D-Calvert) announced Tuesday that he will introduce his own rain-tax-related bill. This was news to his aides, who were unable to provide any details on what the legislation might include.

Sen. James Brochin (D-Baltimore County) co-sponsored Hogan’s bill and introduced his own legislation to repeal the rain tax — something he said an overwhelming number of his constituents have asked him to do.

“This has taken on a life of its own,” Brochin said. “This is a killer for Democrats, especially if you live in my district.”

Scott Clement and Arelis R. Hernández contributed to this report.