As filing opens today, South Carolina's election year will kick into a higher gear, and voters will begin to get a sense of what choices they can make in June's primaries and then in November.

Some campaigns have been waged for many months, such as the governor's race where incumbent Gov. Nikki Haley faces a rematch with her 2010 challenger, Democratic Sen. Vincent Sheheen of Camden. Though that race took an unexpected turn with Friday's announcement from Charleston-area businessman Steve French that he plans to run as a Libertarian candidate.

Other contests aren't as far along, and more surprises could still pop up before filing ends at noon on March 30.

Here's a look at some of the bigger story lines that will play out during the next two weeks.

Will all of Graham's challengers file?

Incumbent U.S. Sen. Lindsey Graham faces the prospect of six or more Republican challengers in the June primary, and while he still has a sizable lead in the polls and in fundraising, part of the party's conservative base remains unhappy with him.

Berkeley County Republicans are expected to meet tonight to consider censuring him.

At least six Republican opponents have begun campaigns, including state Sen. Lee Bright of Spartanburg, Charleston public relations executive Nancy Mace, Orangeburg lawyer Bill Connor, Easley businessman Richard Cash, retired Spartanburg police officer Dave Feliciano, and Columbia pastor and retired lawyer Det Bowers.

It's unclear if they all will file or whether some might drop out. Citadel political science professor Scott Buchanan said the more challengers, the easier the path for Graham, who will need more than 50 percent of the GOP vote on June 10 to avoid a runoff.

"Even if he gets into a runoff, it makes it hard for whoever survives and gets into a runoff with him to consolidate support," he said.

College of Charleston political science professor Gibbs Knotts agreed and said the race will measure the ongoing strength of the tea party movement four years after it first started brewing.

"It's a little unclear to folks who observe this stuff is whether it was a loud movement that has lost some of its political power or is still a real force," he said. "To me, the primary race with Lindsey Graham is really a test case."

Will Scott get free pass?

U.S. Sen. Tim Scott also is up for election this year - for the final two years of Jim DeMint's old Senate term. Haley appointed Scott last year to fill the vacancy created by DeMint's resignation, making Scott South Carolina's first black senator in history. And Scott might cruise in his first Senate election with no primary opposition and little worry in November, Buchanan said.

"I haven't heard about anybody emerging," he added. "Even if someone does, it will not be what we political scientists refer to as a 'quality candidate.' The fact is Tim Scott is well-liked by the tea party, well-liked by the so-called Chamber of Commerce Republicans, so I would not be surprised if he does get a pass."

Knotts agreed everybody expects Scott to win.

"It's a chance for South Carolina to elect an African-American to statewide office, and to have an African-American on the ballot is very historic," he added.

What will the Lt. Gov. field look like?

This year will be the last time South Carolina voters elect a lieutenant governor in a separate vote.

In four years, the governor and lieutenant will be on the same ticket.

Democratic state Rep. Bakari Sellers of Denmark has been campaigning for the post even before current Lt. Gov. Glenn McConnell, R-Charleston, announced he would not run for the seat.

Charleston developer Pat McKinney also has entered the race, and more candidates could emerge for the part-time seat, which pays $46,545 a year and also oversees the state's Office of Aging.

Buchanan said of all the statewide races up this year, he finds this one most intriguing.

"Depending on what happens in 2016, if a Republican becomes president, then Nikki Haley could be offered some position in Washington," he said, so this year's lieutenant governor's race could produce the state's governor for 2017-18.

The S.C. Superintendent of Education race also is shaping up as a lively one, as Mick Zais' decision not to seek re-election has led to a deluge of candidates, particularly on the Republican side.

How many lawmakers will be challenged?

Most sitting South Carolina lawmakers rarely see a serious primary or general election challenge, but there are a few already in the works.

Charleston real estate broker and Republican Russell Guerard has been campaigning for about a year for the District 100 seat held for 20 years by Republican Rep. Chip Limehouse.

And former Dorchester County Council Chairman Larry Hargett is expected to announce that he is mounting a primary challenge to Rep. Chris Murphy in District 98, while Franklin Smith also is expected to challenge Rep. Jenny Horne in District 94.

It remains to be seen how many more challengers will emerge, though a Winthrop Poll released last month indicated Republican voters across the state are generally pleased with the General Assembly. All 124 House members are up for re-election this year, but state senators won't be up for election until 2016.

Filing for all partisan offices - including county council seats, solicitor and other countywide races - also begins today.