A man walks past a 'Stand Up For Steel, Stand Up For America' sign while arriving at the United States Steel Corp. Clairton Plant coke manufacturing facility as emissions rise in Clairton, Pennsylvania.

A new poll shows warning signs for Republicans in Pennsylvania, one of the states most critical to determining which party controls Congress after November's elections.

With just under seven months until the midterms, Democrats have strong advantages both on the generic congressional ballot in Pennsylvania and in the race to hold on to Democratic Sen. Bob Casey's seat, according to a Muhlenberg College poll. In addition, a majority disapproves of President Donald Trump, and a plurality disapproves of the Republican tax law.

Much can change in the months before the elections, and the GOP hopes public opinion of its tax plan can improve and boost the party's midterm hopes. The single poll also does not capture public opinion at the level of specific House districts.

Republicans in recent days have pointed to a shrinking lead for Democrats on the national generic ballot, including a Washington Post-ABC News poll that found only a 4 percentage point advantage for Democrats. They have also highlighted an NBC News/Wall Street Journal poll that found 35 percent of Americans think Republicans are better equipped to handle the economy, while only 28 percent said Democrats are more suited.

Still, the Pennsylvania survey depicts a challenging environment for Republicans in one of the most important states for their effort to hold on to congressional majorities.