Democratic super PAC Priorities USA Action is planning to put some of its money into tight Senate races across the country. 

The group had been initially focused on supporting Hillary Clinton, primarily. But now the super PAC is planning on spending in races in North Carolina, Nevada, New Hampshire and Pennsylvania, CNN reported.

All races are must-wins for Democrats to reclaim the Senate and polling remains tight.

Deborah Ross, a former North Carolina state legislator, has run a surprisingly close race against Republican incumbent Sen. Richard M. Burr.

But Ross, a Democrat, has come under fire from Republicans for her tenure leading the North Carolina affiliate of the American Civil Liberties Union.  The National Republican Senatorial Committee cut an ad alleging that Ross wanted to try a 13-year old who sexually assaulted a woman as an juvenile rather than as an adult.

[Congressional Leadership Fund Hammers Democrats on National Security, Taxes]

In Nevada, Democrat Catherine Cortez Masto, a former state attorney general, has been trailing GOP Rep. Joe Heck in recent polling.

And Democrats Katie McGinty in Pennsylvania and Gov. Maggie Hassan in New Hampshire are in tight races against incumbents.

The Rothenberg & Gonzales Political Report/Roll Call rates the Nevada, New Hampshire and Pennsylvania races as Tossups, while North Carolina is rated as Tilts Republican.