DSCC changes course on Grimes in Kentucky

The Democratic Senatorial Campaign Committee (DSCC) plans to advertise for Kentucky Democratic Senate candidate Alison Lundergan Grimes once again, changing course after last week's decision to cease advertising when it appeared her candidacy against Senate Minority Leader Mitch McConnell, R-Kentucky, was losing steam.

A DSCC official confirmed to CBS News that the group is pouring an additional $650,000 into the race to advertise on Grimes' behalf after internal polling showed the race tightening with undecided voters breaking toward Grimes.

The official did not share the internal numbers, but a Bluegrass Poll from The Louisville Courier-Journal released Monday shows Grimes and McConnell in a virtual dead heat two weeks before Election Day. McConnell was up 44 to 43 among likely voters, a statistically insignificant lead within the margin of error of plus or minus 3.9 percentage points.

Just one day after McConnell and Grimes debated last week, the DSCC made headlines when it declined to reserve any more air time in the race.

An official said at the time that they were continuing to make "targeted investments in the ground game" while monitoring the race for future opportunities.