Solis is a strong supporter of illegal immigration who went as far as helping organize a press conference in Washington DC where supposed U.S. representatives joined with Mexican elected officials to promote comprehensive immigration reform.
Solis said this in 1996:
"We are all Americans, whether you are legalized or not."
She's an opponent of assimilation who joined with Media Matters for America to promote a report designed to silence those few broadcast figures who discuss immigration. See the video and a transcript of her related remarks at the link.
As a California State Senator in 1999, introduced S.B. 371, which would have dropped legal residency requirements to obtain California driver's licenses; the goal was to give drivers licenses to illegal aliens.
From a PBS biography (link):
She hopes to push initiatives granting in-state tuition rates to illegal immigrants, and to expand health care coverage for undocumented workers.
That page also has a picture of her with someone who seems to be Vicente Fox.
"The contributions of undocumented immigrants and the benefits they provide to the U.S. economy more than balance the meager health care resources which they are eligible to receive."
Speaking of which, she supported (link) the CHAMP Act (HR 3162), a children's healthcare bill related to the SCHIP program. While Section 135 clearly states "Nothing in this Act allows Federal payment for individuals who are not legal residents", let nothing stand between a Democrat and their support for race-based power: other provisions let the states establish weak rules for those who declared themselves to be citizens (link). An "audit" would be performed later, and the state would supposedly then reimburse the federal government for any illegal aliens they provided with care. All of that was window-dressing for the goal of giving healthcare benefits to illegal aliens.