Democrats are hoping they can leverage abortion measures to win competitive Senate races.
A concern is voters will vote for both abortion and Republican candidates, Punchbowl News reported.
"We don't want voters to split their freedoms," Planned Parenthood President Alexis McGill Johnson told Punchbowl. "When they split their vote, they are splitting their freedoms, they are canceling their vote, literally."
Abortion measures, which have bipartisan support, are expected to run stronger than the Democrat candidate on the ballot.
"We have a lot of Republicans who are still uncomfortable with identifying as anything other than Republican, but are very comfortable on the ballot measures," Mini Timmaraju, president of Reproductive Freedom For All, told Punchbowl.
In Nevada, Sen. Jacky Rosen, D-Nev., has been on the offense against her opponent, Republican Sam Brown, on abortion. Brown has said he won't support a federal abortion ban, but previously supported a 20-week abortion ban with no exception.
Republicans also opposed messaging bills that Senate Majority Chuck Schumer, D-N.Y., put to vote earlier this year.
"They can say or do anything they want, but their votes show who they are. And they will vote against this every time," Rosen said to Punchbowl. "Don't let them cover up any of this to try to fool us to win a race."
Groups like EMILYs List are working to tie races to the fight over abortion.
"The imperative is to wrap those races around the stakes for reproductive freedom," Jessica Mackler, the president of EMILYs List said. "That's how Democrats have elected candidates on the issue of reproductive freedom in Kentucky and Kansas and many places that are red and purple."