That is a biased view. The Republicans obstructionism is on record during the Obama years, including blocking a potential Supreme Court judge. Remember Merrick Garland?
Democrats crossed the aisle during the Bush years, and legislation passed that was bipartisan like the McCain-Feingold Act and No Child Left Behind and the votes for actions in Iraq and Afganistan. There was more.
Republicans started the current ugliness in politics back when Newt Gingrich and Frank Luntz got together to use the 'right words".
A number of scholars have credited Gingrich with playing a key role in undermining democratic norms in the United States, and hastening political polarization and partisan prejudice.
[7][8][9][58][59][60][61][62][10][63][64][11] According to Harvard University political scientists Daniel Ziblatt and Steven Levitsky, Gingrich's speakership had a profound and lasting impact on American politics and health of American democracy. They argue that Gingrich instilled a "combative" approach in the Republican Party, where hateful language and hyper-partisanship became commonplace, and where democratic norms were abandoned. Gingrich frequently questioned the patriotism of Democrats, called them corrupt, compared them to fascists, and accused them of wanting to destroy the United States. Gingrich furthermore oversaw several major government shutdowns.
[65][66][67][59]
University of Maryland political scientist Lilliana Mason uses Gingrich's instructions to Republicans to use words such as “betray, bizarre, decay, destroy, devour, greed, lie, pathetic, radical, selfish, shame, sick, steal, and traitors” about Democrats as an example of a breach in social norms and exacerbation of partisan prejudice.
[7] .....
According to University of Texas political scientist Sean M. Theriault, Gingrich had a profound influence on other Republican lawmakers, in particular those who served with him in the House, as they adopted his obstructionist tactics.
[9] A 2011 study by Theriault and Duke University political scientist
David W. Rohde in the
Journal of Politics found that "almost the entire growth in Senate party polarization since the early 1970s can be accounted for by Republican senators who previously served in the House after 1978" when Gingrich was first elected to the House.
[68]
Trump brought much of the criticism he received on himself. His own words and actions brought the criticism.