Winning #potus won't mean much for Hillary with an obstructionist GOP Congress
As Obama was taking the oath of office in January '09, GOP leaders were plotting their way back to power. Their plan was to simply say "no" to everything that Obama was in favor of. If that meant gridlock in Congress, then so be it; they'd prefer government shut down than to compromise with the President. In fact, they've done that twice since Obama's first election win, and are making noise as if to deploy the same strategy against Hillary Clinton should she (likely) win in November.
Hillary Clinton may win by a landslide, but her win will be pointless without flipping control of Congress away from the GOP as well. Until the backwards thinking Tea Party movement is beaten out of the Republican party, they cannot be trusted to govern effectively or governm for the whole nation instead of their narrow minded agenda.
Hillary Clinton is not a perfect candidate, Democrats are not without their flaws as well. But unless the gridlock is broken in DC, little will change.