Today's Daily Digit on our fancy new Election Lab dashboard?

40 percent.

North Carolina state speaker Thom Tillis needs to get at least that percentage of the vote in today's GOP senate primary if he wants to avoid a runoff and start planning his general election campaign. If not, he'll have to face off once more with Greg Brannon, the tea party favorite endorsed by Kentucky Senator Rand Paul who keeps edging closer to the lead, and whichever of the other six candidates manage to win enough votes. The runoff is scheduled for July 15, which would mean the eventual GOP victor loses two months of campaigning against incumbent Democratic Sen. Kay Hagan -- and loses two months worth of spending to a protracted primary fight.

North Carolina Republican senatorial candidate Thom Tillis talks to the media after a debate at Davidson College in Davidson, N.C., Tuesday, April 22, 2014. (AP Photo/Chuck Burton)

Recent polling shows that if Tillis doesn't get 40 percent, he will have come this close. The Huffington Post's Pollster average of the race shows Tillis broke away from the competition in March.

Civitas, a Republican-leaning firm, released a poll in mid-April giving Tillis 39 percent of the vote. Brannon had 20 percent.

On Monday, Rand Paul campaigned for Brannon in a rally at the NASCAR Hall of Fame in Charlotte, saying that the OB-GYN with no political experience was the perfect person to pit against Hagan. “The status quo has gotten too strong in Washington, D.C. The Leviathan has gotten too large, Paul said, according to Politico. "As we stand here, the debt clock is spiraling out of control. Send us a champion. Send us a hero. Send us a dragon slayer."

Utah Sen. Mike Lee campaigned for Brannon earlier in 2014. "This guy’s amazing. This man quotes the Constitution more, with greater fluidity, with greater degree of comfort and familiarity than perhaps any other candidate I’ve ever met."

Despite all the dragon slaying and Constitution quoting and precarious polling margins, it looks like Tillis is going to win. The Fix's Sean Sullivan, who will be keeping us updated on the race today, interviewed  a Republican strategist who thinks Tillis has "about a 75 percent chance" of clearing 40 percent.

This is an electoral forecast Republican outside groups and strategists have been desperately hoping -- and spending millions of dollars -- to hear. As the candidate with the most name recognition and most political chops, Tillis had a built-in advantage over his opponents. Not to mention the fact that Brannon has said some ulcer-inducing things on the campaign trail, especially for a political party that has seen its share of campaign-dampening flubs in the past two years. (Tillis, no moderate, has said his share of controversial things on the trail, too -- disputing climate change and ruminating on the end of the Department of Education, for example.)

House Speaker John Boehner has endorsed Tillis, as has Senate Minority Leader Mitch McConnell. Former Republican presidential candidate Mitt Romney endorsed  him on Monday.

American Crossroads, which avoided primary spending in the first two election cycles it played a role in, ran more than $1 million worth of ads supporting Tillis in North Carolina. The Chamber of Commerce has also run ads supporting Tillis. Republican megadonor Paul Singer has held fundraisers for Tillis.

Based on FEC filings, Tillis is also the candidate Democrats are most worried about. Senate Majority PAC has spent almost $4 million in ads against Tillis. Hagan has started running ads against her likely opponent, too.

While the biggest names in conservative campaigning have fought to make sure Tillis makes 40 percent, Americans for Prosperity already has been preparing for his inauguration as the official GOP candidate in the North Carolina senate race. The Koch brothers-affiliated 501(c)4 has run more than $7 million in campaign ads against Hagan in the 2014 election cycle. If Tillis wins today's primary, the amount of money that Americans for Prosperity and American Crossroads decide to sink into the election proper could become the next most important number of the race.