The Democratic Party is on track to regain control of the U.S. Senate in this fall's midterm elections, according to the results of a pair of CNN polls released Monday.

Democratic candidates are leading in two critical Senate races in Republican strongholds. The polls reveal that Rep. Krysten Sinema (D-Ariz.) and former Gov. Phil Bredesen are ahead in Arizona and Tennessee, respectively. The Democratic candidates are vying for two Senate seats left open by two retiring Republican Senators — Sen. Jeff Flake of Arizona and Sen. Bob Corker of Tennessee — who have been publicly critical of President Donald Trump.

Sinema tops Rep. Martha McSally (R-Ariz.) by 7 points — 50 percent to 43 percent among likely Arizona voters and by a similar 48 percent to 41 percent among registered voters. The slight advantage for Sinema in the race to fill Flake's seat could partly reflect the fact that a majority of Arizona voters disapprove of the way Trump is handling his job as president, according to the poll. Sinema also leads McSally in positive favorability, although both candidates are viewed more favorably than unfavorably.