Rep. Martha McSally (R-Ariz.) appears poised to break free from her opponents in a contentious GOP Senate primary battle.
Senator Marco Rubio has given his endorsement to McSally and believes she is the one to help push the Trump agenda in Washington.
McSally, a two-term congresswoman from a swing district in Tuscon, secured a key endorsement from the National Border Patrol Council earlier this week, boosting her conservative credentials in a race that has revolved around that issue.
Republican voters will decide their nominee against liberal Rep. Kyrsten Sinema on August 28.
According to the RealClearPolitics average, McSally leads her closest GOP rival, Kelli Ward, by 8-points and polls consistently show she performs best against Sinema.