Senate Democratic candidates in several key swing states are beating their Republican opponents in the latest round of polling released on Monday that also presented a silver lining for the GOP.

Democrats are ahead in Arizona, Pennsylvania, and Wisconsin but tied with the GOP in Nevada, according to a New York Times-Siena College survey.

The results underscore the challenges that lie ahead for Republicans as Democrats fight to maintain their one-seat Senate majority. But the results also show a promising sign for Republicans, as some have made ground against their Democratic opponents in recent months.

The Democratic Senate candidates are far outperforming their party’s leader in the same states, where President Joe Biden trails former President Donald Trump in all four.

Wisconsin boasts the biggest lead of 7 percentage points for Democrats, with Sen. Tammy Baldwin (D-WI) at 49% to Republican Eric Hovde’s 42%. The margin of error for the state’s results was plus or minus 4.5 percentage points.