The action sets up veto override votes in both houses of the General Assembly next week.
The Senate had planned to vote Thursday on whether to overturn the governor's veto of legislation that would require more of the electricity sold in Maryland to come from renewable sources, such as solar power and wind power.
But when the vote came up, Sen. Stephen Hershey, the minority whip, requested the vote be delayed until next Thursday. His request was granted without opposition.
Hershey, an Eastern Shore Republican, said afterward he wanted to stick to the plan lawmakers had tacitly agreed to: that the House of Delegates would vote on the veto first, then the Senate.
But when pressed by reporters, Hershey acknowledged that Republicans were trying to pick off Democratic votes to thwart the override. Overturning a governor's veto requires a three-fifths vote of the Senate and House.
"We are talking with our colleagues and letting them know that we believe, and the governor believes, that this is a tax," Hershey said.
Last year, 32 of 47 senators voted to pass the bill. To override Hogan's veto, 29 votes are needed.
A handful of environmentalists, expecting an override vote, went to Annapolis on Thursday and held signs outside the State House encouraging senators to vote for the override.
The bill would require one-quarter of the state's electricity to come from renewable sources by 2020, up from the current requirement of 20 percent by 2022.
Advocates say increasing the requirement — known as the renewable portfolio standard, or RPS — is the only way to nudge forward on transitioning to cleaner energy.
Hogan has derided the bill as a "sunshine and wind tax" because it would add costs to consumers' electric bills.
"This legislation is a tax increase that will be levied upon every single electricity ratepayer in Maryland and, for that reason alone, I cannot allow it to become law," Hogan wrote when he vetoed the bill in May.
The vetoed legislation would have added 48 cents to $1.45 a month to the average residential customer's electricity bill, according to a state Department of Legislative Services analysis.
Advocates say any cost increase is a small price to pay for the benefit of cleaner energy.
The House of Delegates is scheduled to take up the veto override Tuesday.
Hogan vetoed five bills passed by the legislature last year. In addition to the renewable energy requirement, he also vetoed bills to increase oversight of the state's mass transit agency, raise money to replace the Harry W. Nice Memorial Bridge in Southern Maryland, give a neighborhood association veto power of a Morgan State University student housing project and create an advisory panel to the state Board of Education.
Lawmakers have yet to take override votes on any of those vetoes. The scheduling of the votes has been complicated, in part, by a number of vacancies in the legislature caused by lawmakers who were elected to other offices, as well as others who resigned for health and other reasons.
The Senate is missing one senator — Baltimore's Lisa Gladden resigned for health reasons. The House has three vacant seats. Replacements have been named for all three, but none of the three has been sworn in.
Lawmakers have overridden Hogan's vetoes before.
During the 2016 General Assembly session, lawmakers passed two bills early enough to force Hogan to sign or veto them during the session. Once Hogan vetoed the bills — which require the administration to rank transportation projects and change the composition of the Anne Arundel School Board Nominating Commission — Democratic lawmakers overrode the vetoes.
Hogan has proposed legislation this year to repeal the transportation bill, which is called the "transportation scoring bill" by Democrats and the "road kill bill" by Hogan and Republicans.
Earlier in last year's session, lawmakers also reversed the governor's vetoes on bills that allow felons to vote as soon as they leave prison, make possession of marijuana paraphernalia a civil offense, change the rules for when police can seize property and money during investigations, allocate $2 million for the Maryland Hall for the Creative Arts in Annapolis, and two that change how certain hotel taxes are collected.