Lindsey Graham Wins Big Over Tea Party Challenger

WASHINGTON - Senator Lindsey Graham of South Carolina was once thought to be among the Republican incumbents most vulnerable this year to a Tea Party challenge. But the most pressing question on Tuesday is not whether he will finish first in the party primary, but whether he can avoid a runoff by capturing more than 50 percent of the vote in a seven-person field.

Mr. Graham has been preparing for this day since the Tea Party showed its strength in 2012 by unexpectedly knocking off a number of incumbents and establishment favorites. The hard-liners have shown little of that muscle this year - Mississippi's results last week being a significant exception - but Mr. Graham's campaign may be the best illustration of how to turn what seem to be disadvantages into victory for Republican incumbents.

He has been hammered by conservative hard-liners in South Carolina, and across the nation, for being an outspoken advocate for an immigration overhaul and for voting to confirm both of President Obama's Supreme Court nominees. But he stockpiled $9.4 million for his re-election, and well before the campaign got underway, he worked to ensure that his biggest potential rivals stayed out of the primary race.

There is considerable unease with Mr. Graham among some of South Carolina's most ideologically driven Republicans, but none of the underfinanced and little-known candidates running against him have been able to take advantage of that discomfort to mount a formidable challenge.

Primaries are also being held Tuesday in five other states - Virginia, Maine, Nevada, Arkansas and North Dakota - but South Carolina is the only one with a high-profile Senate contest.

In Virginia, Republicans used a convention to name their Senate nominee and last Saturday picked Ed Gillespie, an official from President George W. Bush's administration. Mr. Gillespie, who also is a former chairman of the Republican National Committee, will challenge Senator Mark R. Warner, the Democratic incumbent, in November.

The most closely watched Republican House race on the Virginia ballot involves the majority leader, Eric Cantor. He has been under attack from Dave Brat, a Richmond-area college professor who is running to Mr. Cantor's right. Although he is expected to win, Mr. Cantor - who has indicated that he is at least open to some sort of an immigration bill - has been pushed to portray himself as a hard-liner on the issue, drawing criticism from his left and skepticism from the party's most conservative wing.

Mr. Brat's challenge to Mr. Cantor comes as the seven-term incumbent is trying to help wrest control of the state Republican Party from Tea Party-aligned officials. The effort failed at a district convention last month in Henrico County, Mr. Cantor's home base, when conservatives ousted one of his loyalists as chairman while he looked on.

On Tuesday, Mr. Brat's vote total will be seen as an indication of how vulnerable Mr. Cantor, who is next in line to be House speaker, is to challengers from his right, and how the primary race will shape his thinking on immigration.

In Maine, Senator Susan Collins, who has one of the most moderate voting records among Republicans in Congress, has avoided a primary challenge. The contests garnering the most interest there are the Republican and Democratic primaries in the House district now represented by Michael H. Michaud, a Democrat who is running for governor. On the Democratic side, State Senators Emily Cain and Troy Jackson were squaring off. The Republican race is between former State Treasurer Bruce Poliquin and State Senator Kevin L. Raye.

Nevada Democrats will choose among nine little-known candidates in the governor's primary, but none of them are considered likely to defeat the Republican incumbent, Gov. Brian Sandoval, who is in his first term.

In Arkansas, there is only one statewide race, a Republican runoff for attorney general. North Dakota voters will go to the polls in a primary for the state's sole House seat.