The district has traditionally been solidly Republican, but with the 2010 redistricting, and steady urbanization of that region, I wondered if the situation would have changed. Using Tiger geographic redistricting shape files , Indiana election results for 2012, and ACS population data, I created some estimates of who voted for whom at the precinct-level in 2 specific races--Attorney General, and School Superintendent. As background for these races, AG Zoeller was running for his 2nd term, being active in far-right political cases (like submitting anti-gay-marriage amicus briefs to various cases around the country), and School Superintendent Tony Bennett had been a charter-school activist while in office. Zoeller won his 2012 run, but Bennett lost to Glenda Ritz, despite the GOP sweeping the rest of the offices in the state, including electing a supermajority in both Senate and Representatives chambers.
In what is now the newly redistricted D29 for senate (some of these counts are estimates based on precinct line changes), Zoeller (R) won approximately 57% of the vote, while Ritz (D) won approximately 51% of the vote. There are several factors working in Delph's favor. First, he has an incumbent advantage. Second, he has the party advantage for the "6 year presidential itch;" i.e., in the 6th year of an incumbent president's term, the "other" party (in this case, Republicans) tend to have an advantage. Third, he has a turnout advantage--midterms tend to favor GOP. Fourth, he has the numbers in this district--Zoeller beat his competitor by a wide margin.
However, several factors may also come into play. The hit that he took by the senate majority leader, and Delph's very public meltdown about the same-sex marriage issue, which was accompanied by several very insulting remarks about what makes a "true" Christian (i.e., "any professed Christian minister that teaches any sin is acceptable is NOT acting in true love but in eternal condemnation #truth"), and arguably "crazy" comments on several other issues, may cause voters in his district to question is ability to represent them. While midterms already have miserably low turnout (usually about 1/3 of registered voters come out to midterms in the Marion County area), some typically stalwart GOP in his district may be incentivized to stay home rather than be forced to choose between Delph and the gay Democrat. And as demonstrated in the 2012 elections, D29 voters are more than willing to vote for the Democrat if they like the candidate, rather than simply doing a party-line vote.
Any of these factors could shift the vote in Ford's direction. Additionally, the demographic numbers that we have for that district are largely from the 2008-2012 ACS--but that entire area is dramatically and rapidly changing, largely in the direction of younger voters, and race minorities, so the influx of new residents, if they register and vote, will mostly be potential Ford voters, especially when given the choice between Delph and Ford.
In terms of raw numbers, there are about 100k residents in D29 over 18 (2012 ACS 5-year estimate), with an average age of 36, 52% female, and 69% White. But these estimates are 2-6 years old--a lot has changed in 2 years in that area. According to my redistricting estimates above, there were about 60k votes cast in the 2012 election, so perhaps half of that will show up for the midterms. Much of the new housing in the area, because of the recession and housing price bust, has been apartments, which will bring in voters more inclined towards Democrats (younger, poorer, single females).
Maps of the redistricting, by % of vote for AG and School Superintendent, are below.