Braun identified himself as a career businessman - rather than career politician, which is what he called his opponents, IN congressmen Luke Messer and Todd Rokita.
But the Republican primary races in those states have been contentious, filled with decades-old feuds and controversial candidates - among them a former coal executive who has attacked Senate Majority Leader Mitch McConnell in unusually personal terms.
It remains to see if Braun can outspend and out-campaign Joe Donnelly the same way he did his Republican rivals come November 6 and the general election.
Cordray defeated Dennis Kucinich, the former Cleveland mayor, member of Congress and presidential candidate, in a battle of liberal favorites.
Braun says he voted in Democratic primaries in the past because in his southern in home Democrats held all the local offices. They hope the winners will unseat what they see as vulnerable GOP incumbents in November.
There are four primary elections for the 2018 midterms on Tuesday, May 8, occurring in Ohio, Indiana, West Virginia and North Carolina.
The primary between Braun and his fellow contenders, sitting Congressmen Luke Messer and Todd Rokita, turned nasty with accusations thrown at all candidates.
At the same time, the three fell over one another to assert they'd be President Donald Trump's biggest ally in the Senate. While Braun has said he is a "lifelong conservative", he has voted in Democratic primaries and CNN reported that Braun was listed in RNC voter data as a "hard Democrat" until at least 2012.
Braun, a former state legislator, put more than $5 million of his own money in the race and will be expected to spend liberally again to challenge Donnelly in Indiana. The Washington Post's report on the Senate primaries notes that Republican voters actually did a pretty good job of choosing competitive candidates this time around, as opposed to, oh ...
Republicans also waged bitter Senate primary battles in IN and OH, two other states that Trump won in 2016 and where incumbent Democratic senators are up for re-election this year in key races in the battle for control of Congress.
Braun has campaigned on his business background and has pledged to bring back jobs that have been outsourced overseas.
"We're of course disappointed with the results of this election, but as Jennifer (his wife) was saying to me over the weekend, 'Look, we are very confident that God has great plans ahead for our nation, our state and the Messer family", Messer said.
"If Senator Donnelly doesn't approve it, because, you know, he's on the other side, we will come here, we will campaign against him like you wouldn't believe", Trump said at an Indianapolis rally last September.
Candidates are eyeing those districts that used to elect conservative Democrats before they were redistricted to favor the GOP after the 2010 census.
Rokita is now the congressional representative from Indiana's Fourth Congressional District, though he also spent time as the Indiana Deputy Secretary of State and Secretary of State before stepping into his current role.
Lamb has criticized his opponent for relying on the Pence name, which is well-known in the district that Pence's younger brother, Vice President Mike Pence, held for a dozen years before becoming in governor.
Trump and Vice President Mike Pence have already scheduled a campaign event in IN on Thursday, indicating the priority the White House is putting on the in race - and their willingness to back whoever emerged from the primary.
We sat down for a one-on-one interview with businessman Mike Braun when he was in our area last week. For a full year, the two congressmen have been at each others' throats. They hope the increase is a sign that they could cut into Republican supermajorities in the state House and Senate that have left them largely powerless over the past six years.