4. The O'Malley effect: It's often the case that governors leave office on poor terms with the public. Luster fades, scandals creep, and finicky voters start to search for fresh faces. Sitting governors, too, often shy away from wading into primaries and endorsing candidates to succeed them.

But none of that looked to be true on Tuesday night in Maryland, where outgoing Democratic Gov. Martin O'Malley, a potential presidential candidate in 2016, had taken something of a gamble heading into Election Day. He endorsed a pair of statewide candidates who ultimately coasted to primary wins by embracing his progressive policies and his popularity with rank-and-file Democrats (His approval rating among Democrats reached almost 80% in a Washington Post poll earlier this year).

In the state's attorney general primary, O'Malley's preferred candidate, state Sen. Brian Frosh, defeated Jon Cardin, the nephew of Sen. Ben Cardin.

And in the state's marquee gubernatorial primary, Lt. Gov. Anthony Brown thumped his main opponent, the gaffe-prone Attorney General Doug Gansler, by draping himself in the O'Malley banner, happily boasting about the state's premier education rating among other policies.

Gansler struggled to draw a contrast with Brown, O'Malley's anointed successor. When Gansler raised questions about the state's troubled health care exchange rollout and tried to tie the problems to the lieutenant governor, Brown accused Gansler of attacking Obamacare. Running against O'Malley in a Democratic primary was mostly futile.

Fresh off a buzzy trip to Iowa last weekend, O'Malley bolstered his political standing back home on Tuesday. All in all, a pretty strong week for one of the Democratic Party's leading alternatives to Hillary Clinton.

5. If at first you don't succeed...: Twenty-four years after he first ran for lieutentant governor, South Carolina's Henry McMaster is a major step closer to finally winning the office. The former state attorney general easily won the GOP primary runoff, topping businessman Mike Campbell, the son of the late Caroll Campbell, a popular Republican governor.

A former U.S. attorney, McMaster's the ultimate political insider, serving nearly a decade as chairman of the state's Republican Party. With a win in November, he'll be considered a contender for governor in 2018.

What made this race interesting to a national audience was that two former Republican presidential candidates who may run for the White House again in 2016 took sides.

In the closing days of the runoff campaign, former Sen. Rick Santorum of Pennsylvania stumped with McMaster while former Arkansas Gov. Mike Huckabee campaigned for Campbell.

South Carolina plays an important role in presidential politics -- its primary is the first in the South each cycle.

"It's a big win for McMaster but a big win for Santorum as well," GOP consultant Bruce Haynes, a South Carolina native, told CNN. "Santorum already had bona fides with faith and values voters. Now he's wisely allied himself with the dominant figure in South Carolina's GOP establishment. Santorum is doing the quiet but important work of building an organization, and he had a very good night in the Palmetto State."