Yes we have 15 million green card holders in this country. Some do not choose the option of citizenship. Others are waiting the allotted time period before they can apply.
The Democrats have developed something called the New American initiative to assist green card holders in becoming citizens. The Governor of Maryland set up an office to do that and there is a bill in the General Assembly in VA to set up a similar office. The Dems will use it as a feeder/contact system to identify Dem voters. Immigrants vote more than two to one Dem. The more they can encourage and assist green card holders in becoming citizens, the more voters they will have.
No doubt Martin O Malley did that.
He also gave illegals drivers licenses.