"Probably the last time it was relevant was 35, 40 years ago," said distinguished professor of history at American University and author of "The Keys to the White House," Allan Lichtman, referring to the 1976 primary between Ronald Reagan and then-President Gerald Ford.
The Republican primary has become a race to the magic number of 1,144 delegates that would give a candidate the nomination. Former Massachusetts Gov. Mitt Romney has the lead with 558 delegates, former Sen. Rick Santorum has 273, former House Speaker Newt Gingrich has 133 andRep. Ron Paul has 50.
"This is a contest for delegates and every delegate counts. And Maryland's 37 delegates count," said Lichtman.
Maryland's delegates are allocated through a combination of a winner-take-all system and a proportion distribution. The primary is also closed, meaning only registered Republicans can vote.
Each congressional district has three delegates who must vote for whomever wins their district, while the remaining 13 delegates are awarded to the candidate who wins the overall state vote.
The delegate system may benefit Santorum, who could do well in Eastern Maryland's 1st District, but Romney will likely win the state and the extra delegates, Lichtman said.
Romney has a 17-point advantage over Santorum, according to a poll conducted by Rasmussen Reports on Wednesday. It showed Romney is supported by 45 percent of Maryland Republicans, Santorum with 28 percent, Gingrich with 12 percent and Paul with 7 percent.
"Maryland is a more moderate state. It's south of the Mason-Dixon Line, but it's got very different politics than Louisiana," Lichtman said.
Registered Democrats outnumber Republicans more than two to one and Maryland hasn't selected a Republican president since 1988. Democrats are the majority in the state House and Senate, hold six of the eight congressional districts and retain both U.S. Senate seats, as well as the governor's office.
Still this year, Republican candidates are visiting Maryland. Romney was in Arbutus March 21 to rally support in suburban Baltimore. Romney's Maryland campaign co-chairman Louis M. Pope said so many people attended that 250 people couldn't get into the venue, which holds about 350.
"We're anticipating a good day on Tuesday. … Hopefully, Maryland will put him over the top. Hopefully, our opponents will begin to see reality," Pope said.
Newt Gingrich spent March 27 in the Old Line State, visiting near the State House in Annapolis and speaking with students at Salisbury University. Rep. Andy Harris, a Republican from Cockeysville, is a co-chairman of Gingrich's Maryland campaign.
Ron Paul held a town hall at the University of Maryland's College Park campus March 27. One of the strongest cheers of the night came when Paul declared the fight for delegates wasn't over.
"I know we're not going to win Maryland," said Ron Paul volunteer Brent Robbins, who added that Paul's success lies with the district-allocated delegates. "I think we can get them here tonight. … What they did in Virginia is they were able to get a lot of delegates when he came to Springfield."
Santorum has not visited Maryland.
Last week's early voting brought more than 76,000 Marylanders to the polls. This year's election is not only a heated Republican presidential primary race, but a competitive race in several Congressional Districts.
"We're seeing some really competitive primaries in our open districts—both the 4th and 6th," said Matthew Verghese, Maryland Democratic Party political and communications director.
"I don't expect it to be as high as it was four years ago, but I think we'll have a real respectful turn out on Tuesday…making sure we have some gains here in Maryland so we take back the House and keep the Senate."