GOP lawmakers are getting nervous about next year’s election as polls show President Trump’s approval rating dropping during the 28-day government shutdown, with economic experts warning that the standoff could dampen economic growth significantly.

Rove advised lawmakers at the meeting not to rely too much on the conservative base, which is solidly behind Trump in the stalemate over funding for a border wall, and to remember the importance of expanding the GOP’s appeal, according to Republicans familiar with his remarks.

“He talked about politics being about addition and multiplication. You want to continue to bring people in who support you and the ideas that you’re presenting to help the country move forward in a productive way,” said a GOP senator who attended the meeting.