McConnell to campaign for Mourdock in Indiana's Senate race

Mourdock beat incumbent Sen. Dick Lugar (R-Ind.) in the Republican primary earlier this year and is facing a tougher than expected challenge from Democratic Rep. Joe DonnellyJoe DonnellyOvernight Finance: Trump threatens NAFTA withdrawal | Senate poised for crucial Puerto Rico vote | Ryan calls for UK trade deal | Senate Dems block Zika funding deal Senate Democrats block Zika agreement ahead of recess Post Orlando, hawks make a power play MORE (Ind.). Lugar decided not to help or campaign for Mourdock after he was defeated in the primary.

ADVERTISEMENT
Donnelly has argued that Mourdock, a Tea Party favorite, is too extreme and conservative for the centrist voters in Indiana, who had elected Lugar by a landslide in the past.

Other Republican senators, such as John McCainJohn McCainBush World goes for Clinton, but will a former president? GOP senator: Trump could lose Arizona Senate panel passes bill that would create 4K visas for Afghans MORE (Ariz.) and Lindsey GrahamLindsey GrahamOvernight Defense: US blames ISIS for Turkey attack | Afghan visas in spending bill | Army rolls up its sleeves Senate panel passes bill that would create 4K visas for Afghans Trump: Rivals who don't back me shouldn't be allowed to run for office MORE (S.C.), have gone to Indiana to campaign for Mourdock. 

The Indiana seat is viewed as a critical win in order for Republicans to get control of the Senate.

Democrats are defending 23 Senate seats compared to just 10 Republican seats, but thanks to good recruiting and a few GOP fumbles, Democrats have been able to stay competitive in states — such as Indiana, Missouri, North Dakota and Maine — that were once thought of as potentially easy pick-ups for Republicans.

More in Senate

GOP senator: Trump's judge remarks 'unacceptable'

Read more »