DSCC spending money to save Sen. Specter in May 18 primary

The Democratic Senatorial Campaign Committee (DSCC) is spending money on Sen. Arlen Specter's (D-Pa.) increasingly difficult primary.

As poll numbers show Rep. Joe Sestak (D-Pa.) catching up to the senator, a source confirms the DSCC is spending coordinated funds for Specter. The spending was first reported by my former colleague, Reid Wilson.

Coordinated funds differ from most party spending in that the committee can use the money to work with the candidate and supplement his or her ad buys. But such funds are capped at a certain amount depending on the race — $855,400 in the Pennsylvania Senate race — while non-coordinated or independent expenditure funds can be spent in unlimited amounts.

The DSCC has openly backed Specter over Sestak, but actually spending money on the race is a more unusual step. Specter is also getting an assist from President Barack ObamaBarack ObamaFirst lady slams Trump's 'birther' comments Obama's contradictory stance toward black asylum seekers Webb: After the debate MORE, who has cut a radio ad for him.

The committee spending has already led the National Republican Senatorial Committee (NRSC) to ask whether the DSCC will do something similar for Sens. Michael BennetMichael BennetEconomists have a message: Clinton's policies are wrong for America Senate rivals gear up for debates Grassley pulling away from Dem challenger MORE (D-Colo.) and Blanche Lincoln (D-Ark.), who both face primaries as well.