Democrats drew level with Republicans in a congressional preference poll ahead of the U.S. midterm elections, driven by a boost to President Joe Biden’s approval rating and the political focus on abortion.

The NBC News survey of registered voters showed the parties at 46% each, suggesting possible momentum for the Democrats after they trailed by 2 percentage points in a similar survey in August. The differences in party support were within the margin of error in both polls.

Biden made up ground with core factions of the Democratic base as his approval rating jumped 45%, a 3-point increase over August and the highest since October, according to NBC. Former President Donald Trump’s favorability fell to 34%, one of the lowest levels since he left office.

The GOP maintained all-time high advantages among voters on the economy, crime and border security, while Democrats hold a record advantage on abortion and double-digit edge on health care. The poll showed 61% disapproving of the Supreme Court’s decision in June to overturn the federal right to abortion in Roe v. Wade, compared with 37% who approve.

“There is a campaign about the economy, cost of living, crime, and border security, and Republicans are winning this campaign,” GOP pollster Bill McInturff of Public Opinion Strategies was quoted as saying. “But there is a second campaign on abortion, democracy, and climate change, and Democrats are winning that campaign.”

The Sept. 9-13 poll of 1,000 registered voters has a margin of error of plus or minus 3.1 percentage points.