College Democrat view
Contrary to some claims, Democrats are not in support of open and unchecked borders. In short, yes, crossing the border without authorization is and should be an illegal act. That being said, it is important to distinguish the difference between legality and criminalization of crossing the border. Prior to 1929, crossing the border was a civil offense, not a criminal one. This means that those found crossing the border, still illegally, could in fact be deported back to their country of origin as opposed to being prosecuted in an American court. Criminalization of illegal crossings, under Title 8 of US Code, mandates that offenders be prosecuted and/or fined, taxing the American judicial system at a higher rate than it would be if illegal crossings were still treated as a civil offense.
Illegally crossing the border became a criminal offense when Sen. Coleman Livingston Blease of South Carolina, an unapologetic white supremacist, proposed that Congress pass a law criminalizing those who did not cross the border through official crossings. These official points of entry were few and far between and often required that immigrants pay a fee and submit to tests. Although the law applied to all immigrants, regardless of national origin, the intent was to restrict immigration from Mexico.
According to the Brookings Institution, 62% of undocumented immigrants in the United States came here by legal means and have simply overstayed their visas; this is a contrast to the rhetoric of the Trump administration related to border crossings. On Nov. 14, in the Department of Homeland Security proposal, the Trump administration announced its intent to raise the cost to become an American citizen by 83 percent, a rule aimed to exclude low-income and working-class immigrants from acquiring citizenship. This new rule will only exacerbate the factors that cause immigrants to overstay their visas, as opposed to seeking citizenship.
Treating undocumented immigrants like criminals is not a practicable solution. It has not worked since it was implemented 90 years ago and it will not work 90 years from now. If we are going to fix our broken immigration system, it needs to begin with reforming the approach we take with criminalization of border crossings.