Hillary and Obama were anti-gay marriage before they were for it. You don't see that as political expediency?

The Democratic party was for controlling immigration to protect low-skilled American workers and in favor of a border fence before they were for lax enforcement and talking about open borders. Heck, Harry Reid was once proposing to get rid of birthright citizenship.

"But those who enter our country illegally, and those who employ them, disrespect the rule of law. And because we live in an age where terrorists are challenging our borders, we simply cannot allow people to pour into the United States undetected, undocumented, and unchecked. Americans are right to demand better border security and better enforcement of the immigration laws." -Sen. Barack Obama, 2006.  Sounds a lot like the Trump campaign of 2016, doesn't he?