Martha McSally is an Arizona Republican, and as such should, of course, be standing up for the defense of the United States against illegal aliens. Whether because of donor influence, or because she's so "bipartisan", until recently she hasn't been. During the 2016 campaign, she refused to endorse Trump, viewing him as anathema to women, partly because of the Access Hollywood tape.
She's also been really squishy on illegal immigration. The Washington Post says that's changed:
In May, McSally removed herself as a co-sponsor of a bill that offered a path to citizenship for certain young undocumented immigrants. In June, a video of her talking sympathetically about young undocumented immigrants was removed from her congressional website.
by Sean Sullivan July 7, 2018
I don't know if McSally has actually reformed, or if she has figured out that American voters, especially in Arizona, are tired of illegal immigration. My favorite saying about this kind of politics is that it doesn't matter if a politician sees the light, as long as he feels the heat.
That's clearly what McSally is doing--and in Arizona, the temperature right now is 109 °F.